United Nations: UN Secretary-General Ban Ki-moon on Thursday called on Kiev and pro-Russian rebels to immediately stop fighting to allow investigators to reach the crash site of the downed Malaysian plane.
"The families of this horrific tragedy deserve closure and the world demands answers. International teams must be allowed to conduct their work," said Ban in a statement released by his spokesman.
The appeal came after investigators and forensic teams from the Netherlands, Australia and Malaysia were forced to turn back for the fourth consecutive day, due to fighting between Ukrainian forces and separatist fighters in east Ukraine.
Saying he was "deeply disturbed" by the developments, Ban called "on all parties to immediately halt hostilites in the proximity of the crash site so as to allow the international teams unimpeded access to the site."
"There are victims' remains yet to be found," Ban said, and "key pieces of evidence remain at the site."
Over 200 bodies from the 298 victims of the 17 July crash have been recovered from the site and sent to the Netherlands and there have been concerns of evidence tampering.
The UN Security Council last week adopted an Australian-backed resolution condemning the downing of the passenger plane, demanding that all military operations cease and calling for a full investigation.
Russia and Ukraine have traded accusations over the fighting in east Ukraine, with Kiev accusing Moscow of backing the separatist rebels and most likely providing the weaponry that brought down the passenger plane.
Kiev said its troops were pressing on with an offensive to take back towns near the downed jet, with a "mopping up" operation ongoing in the town of Ilovaysk, some 40 kilometres away.
The army said troops had also taken the town of Avdiyivka, a dozen kilometers to the north of Donetsk.
Fighting also raged around another insurgent stronghold, Lugansk, where local authorities said one civilian died and ten were injured in the past 24 hours.