Beirut: Kurdish and Arab fighters aided by US soldiers have battled the Islamic State group north of its Syrian stronghold of Raqa as Iraqi forces edged towards the jihadist-held city of Fallujah.
The twin offensives are two of the most significant ground assaults against the extremists since they declared a self-styled "caliphate" straddling Iraq and Syria in 2014.
The assaults came as Syria's UN envoy said trapped civilians risk starvation unless Damascus and rebel groups allow greater access to humanitarian aid convoys.
The UN Security Council is to discuss today the humanitarian situation in Syria and the possibility of parachuting aid to besieged cities.
Near the front line north of Raqa city, an AFP photographer saw US soldiers on Wednesday assisting a Kurdish-Arab alliance known as the Syrian Democratic Forces.
The SDF is working its way through villages and farmland south of the town of Ain Issa, less than 60 kilometres (40 miles) from Raqa city.
It said its fighters had "advanced seven kilometres from Ain Issa and liberated five villages and four fields."
"We liberated the villages of Fatisah, Namroudiya, and Wastah as well as several fields. The coming battle will hold a lot of big surprises," SDF field commander Baraa al-Ghanem told AFP.
The Syrian Observatory for Human Rights said SDF fighters yesterday were shelling Islamic State positions near Ain Issa as the US-led coalition carried out nearly non-stop air raids.
The Britain-based monitor updated its toll for the five-year war to more than 280,000 dead.
A fragile truce agreed between the US and Russia in February had curtailed Syria's bloodshed despite consistent allegations of violations, but the international fight against Islamic State was excluded from the ceasefire deal.
The first of 250 members of the US special operations forces were due to arrive this week in northeast Syria to support the campaign, joining dozens of advisers already on the ground.
An SDF field commander told AFP that US ground forces were "taking part" in operations north of Raqa.
"There are US forces using (anti-tank) TOW missiles to fire on the explosives-rigged cars that (Islamic State) is using to attack the SDF," said Hawkar Kobane.
Asked about the men seen on the front line, US defence officials did not dispute that they were American special operations forces.
Observatory head Rami Abdel Rahman said Islamic State is "concentrating 2,000 fighters along the front lines north of Raqa" to repel the SDF offensive.
"Islamic State has prepared for this fight in recent months by digging tunnels and lining them with explosives, as well as preparing car bombs and hiding in buildings among civilians," Abdel Rahman added.
Updated Date: May 27, 2016 19:04 PM