8. 28 pm: New Power Minister Veerappa Moily had said he will speak to his predecessor Sushilkumar Shinde and take stock of the current situation. He also said that the states cannot be blamed for today's situation, and he will do everything possible to fulfill his responsibilities.
"Cannot start with blame game on states. We will have to keep in touch with the development of the country," he said.
8.00 pm: Northern and Eastern grids have been partially restored. Latest reports say 75 percent of power has been restored in North. 60 percent of train services have also been restored.
Outgoing Power Minister Sushilkumar Shinde told reporters that power supply has been restored fully in the North-East and it will take a few more hours to resume supplies in other parts of country hit by the outages.
7.10 pm: Reports coming in that power supply to Delhi metro has been completely restored. Over 45 percent in North, and 35 percent in North East have been restored.
Meanwhile, new Power Minister Veerappa Moily says he will meet PM, Sonia Gandhi on power crisis. In an interview to NDTV, he says, "people need to manage power better."
7.05 pm: Following Uttar Pradesh, Punjab has also issued a denial, saying it did not overdraw power. Punjab government issued a statement saying, "claims that Punjab overdrew power is baseless and misleading."
6.40pm: Uttar Pradesh Chief Minister Akhilesh Yadav has refuted charges that the state was responsible for today's power outage because it continued to overdraw from the Northern grid even when it was not completely stable.
The government statement said that the state was not overdrawing power today and have denied responsibility for the collapse today which plunged 20 states and 600 million people into crisis. It adds that the parameters and the timing of the collapse shows that UP was not responsible.
However the Times Now channel says it has data to show that the state was overdrawing power both yesterday and today, which could have led to a domino effect and tripped not just the Northern grid, but also the Eastern and North eastern grids.
6.33pm: Power is reportedly back in parts of New Delhi. Power Minister Sushil Kumar Shinde said earlier that he expected normal power supply to resume across all affected states by 7pm.
6.00pm: The Central Electricity Regulation Commission (CERC) has reportedly issued a notice to the UP government to appear before it on 16 August and explain why it continued to blatantly overdraw power and ignore warnings given to it earlier.
The UP government has been asked to provide an explanation for its actions or face serious consequences.
The Times Now channel reported that severe overdrawing from UP had caused the Northern grid yesterday, and added that they had continued to overdraw power from other grids today which led to a domino effect and the collapse of three other grids today. The state, along with Punjab and Haryana had been overdrawing power since 1 January 2012.
The report added that Power Minister Sushil Kumar Shinde had also written to Prime Minister Manmohan Singh complaining that Akhilesh Yadav's government was not sticking to the prescribed quota.
Meanwhile Bihar Chief Minister Nitish Kumar denied that his state had overdrawn power, and added that he expected power to return to the state by 9pm.
5.36pm: Minister of power and energy Sushil Kumar Shinde has said that action will be taken on states overdrawing more power. "I appeal to states to stick to allocated quota. I have told officers to fine states that take more power than allocated. Our ministry kept notifying those states that were extracting extra power. States taking more power than they should has become a problem again for the nation", he said.
The Minister also said that the situation was also improving. "There is a 45% improvement in Northern sector, 35% improvement in Eastern, 100% in North-East, and an improvment of 2000MW in Delhi.
5.01pm: As many as 200 miners are reportedly trapped underground in a coal mine in Burdwan district of West bengal.
West Bengal Chief Minister Mamata Banerjee said due to the power failure, the lifts were not operating, leaving the miners trapped inside.
"We are trying to rescue the coal miners. All efforts are on to resume power supplies. You need power supplies to run the lifts in the underground mines," Mamata Banerjee told reporters in Kolkata.
The mines are operated by the government-owned Eastern Coalfields Ltd.
4.21pm: Chairman of the power grid Ram Naik has said that power should be restored completely in all 12 affected states by 7pm, adding that while an overdrawing of power by some states was responsible for yesterdays breakdown, power officials were yet to ascertain what happened today.
"The blackout was due to the interconnection of grids. We are still investigating the matter", said Naik to a large gathering of media who were clamoring for answers. However he expressed confidence that normalcy would return in a few hours.
Naik also appealed to the media to spread the message that the power grid officials knew what they were doing. "We are professionals, our job is to ensure this doesn't happen again. For the last 10 years, did power grid fail? You have to trust us", he said.
3.57pm: The BJP has hit out at the government, after a power failure in the Northern and Eastern grids, plunging much of India into crisis for a second day in a row. BJP spokesman Prakash Javadekar said the crisis was a manifestation of mismanagement by the government. "For the last two days the country is suffering. This is an unparalleled occurrence", he said.
"The whole machinery has failed to locate the exact fault and yet pushed the entire load onto it. The country could suffer tomorrow also", he said, adding that it was essential that the Prime Minister answered.
Gujarat Chief Minister Narendra Modi also weighed in on Twitter:
3.30pm: With the failure of the Eastern grid and the resulting power outage in Kolkata, West Bengal Chief Minister Mamata Banerjee has declared a holiday in the state to allow people to return home safely. Government offices and schools have been shut down.
3.21 pm: New media reports just coming in, have said Minister of Corporate Affairs Veerappa Moily will take additional charge of power. No further details were immediately available.
3.13pm: Uttar Pradesh has denied reports that the state is to blame for the failure of the Northern grid, because the state was overdrawing as much as 26 million units of power from the grid every day.
"We have not been overdrawing power. This is a wrong allegation", said the head of UP's power and energy board to CNN IBN.
A report has said that UP was over drawing an excess of 26 million units of electricity per day. Reports also say Haryana has been over drawing power of 13 million units and Punjab overdraws 5.2 million units every day.
3.00pm: Emergency services have begun receiving power in Delhi. The latest reports say that partial services have resumed on all lines of the Delhi metro. The trains will now run on a frequency of every ten minutes.
Meanwhile some railway lines have also begun functioning. Power supply has been partially restored in the Mathura rail route. Train movement has begun.
2.50pm: Power Ministry Sources have said that the Eastern grid is slowly coming back to life. Power has been partially restored to Odisha thanks to inputs from the Southern grid and hydro power. Additionally there is now power in 20% of East India, and 50% of the Northeast. Mizoram,Manipur,Tripura are also reportedly completely back to normal.
2.41pm: The latest reports coming in say that normal power supply should be provided to all 12 affected states by around 6pm this evening. This piece of information comes on the back of a statement by Minister of Power and Energy Sushil Kumar Shinde who promised the restoration of emergency power in one and a half hours.
The Western Grid is reportedly involved in helping the restoration of power to the Northern grid and Eastern grids by providing connecting lines.
2.26pm: Minister of Power and Energy Sushil Kumar Shinde has said that emergency power will be restored to states affected by the Northern and Eastern grid collapses in another one and a half hours. "We will try to restore services of metro and railways first", he said.
The Minister added that the Bhakra Nangal plant has been started and that hydel power was currently being drawn for Punjab.
Shinde said the crisis had been caused by some states overdrawing from the grid, but did not name which states were responsible.
2.21pm: With the failure of the power grids, more than 600 million people are left without electricity, in what is one of the world's most widespread power failures. In Delhi, 4000 personnel have been pressed into duty to handle the traffic situation in Delhi.
Routes to avoid in Delhi as of now are CP inner and outer circle, Asoka Road and Baba Kharak Singh Marg.
4000 personnel pressed into duty to handle traffic situation in Delhi.
Reports just coming in say that the grid failure is on account of failure in transmission lines
2.09pm: It has now been confirmed that 12 states have been affected by the grid collapses. Meanwhile a statement from the power ministry has said that essential services be restored in the next two hours. This would translate to power for hospitals, VVIP areas, trains etc. There is still no word on when power to homes and offices will be restored.
Meanwhile the word on Twitter is that the Kolkata metro is up and running:
In Delhi, the DMRC has said that all trains have been moved out of tunnels, to nearby stations for evacuation.
2.04pm: As many as 300 trains in North India alone have been affected by the collapse of the Northern and Eastern grids, with many more trains likely to have been impacted in the Eastern states. NDTV reported that train services are halted in Asansol, Sealdah, Howrah divisions in West Bengal after failure of the Eastern grid.
The CPRO Northern Railways, Neeraj Sharma, speaking to CNN-IBN, said they will try to run some trains and make alternative arrangements like diesel power. The Delhi and Kolkata Metros are also not running.
1.55pm: The reason for the grid failures in the North and East have reportedly been caused because frequency has dipped below the optimal level of 48Mhz. However officials have been unable to identify exactly where the fault has occurred., so it will take more time for them to get the grids back up and running. Meanwhile officials have said that Delhi's VVIP areas will receive 100 MW of emergency power.
1.47pm: Rail services have been severely affected once again, with 75 trains affected in Northern railways. Another 125 trains are held up between the Ghaziabad and Mughalsarai divisions.
The Delhi metro is also at a complete standstill. DMRC officials have asked govt if hydel project in Bhutan can be used again today to run essential services.
Meanwhile all govt hospitals have switched to in-house power back-up. A press statement has said that ICUs can be operated comfortably for a few hours at least.
1.43pm: Minister of power and energy Sushil Kumar Shine speaking to CNN-IBN, has said that officials are investigating the reason for the failure of both the Northern and Eastern grids. However he said that it was highly likely that the outages were being caused by states who are overdrawing power from the grid.
Meanwhile officials have said that a reason for todays outage could also be a surge of power frequency from the Western grid. They have also warned that in terms of the Eastern grid, it was unlikely that power could be restored until tonight.
1.35pm: Just when North India thought a nightmarish power crisis was behind them, the Northern and Eastern grids have failed again. This time however, the crisis is even worse with large parts of East India also coming under darkness. The grid collapse reportedly occurred at 1:07pm
The metro trains have stopped moving completely, and the DMRC is reportedly trying to move trains to the nearest station. HT tweeted that an evacuation process was under way.
There is no power in Delhi, Haryana, Punjab, Himachal Pradesh, UP, Rajasthan Jammu, Orissa and Kashmir and Haryana. Power outages are also being reported from West Bengal, Jharkhand and Bihar.
Meanwhile CNN-IBN said that all electric trains are standing still in the three railway zones of Northern Railways, North Western Railways and North Central Railways.