Syrian regime closer to Daesh hit

Russian-backed Syrian regime forces inched closer on Monday to a key stop on a vital Daesh group supply line, as a twin offensive bore down on the northern stronghold.

The advance comes as 17 civilians were killed in air raids on a popular market in eastern Syria on the first day of Ramadan.

The UN, meanwhile, backtracked on its plan to move ahead with airdrops of humanitarian aid to Syria, saying it was focusing for now on security access for land convoys.

"Our main focus is on land delivery, given the challenges in terms of safety and logistics of air deliveries," UN spokesman Stephane Dujarric said.

In the battleground town of Tabqa, Daesh fighters are caught between Russian-backed regime forces pushing from the southwest and US-supported Kurdish and Arab fighters from the north.

The Syrian Democratic Forces (SDF), led by the Kurdish People's Protection Units (YPG), last week launched an operation against Tabqa and a nearby dam from the north of Raqa province.

But while they remain 60 kilometres north of Tabqa, government forces advanced on Monday, the Syrian Observatory for Human Rights said.

Regime fighters are now within 24km of Lake Assad, the key reservoir in the Euphrates Valley contained by the Tabqa Dam, said the Britain-based Observatory.

Observatory head Rami Abdel Rahman said regime forces were "reinforcing their positions" south of the town, and are less than 25km from Tabqa airport.