US-backed Syrian fighters battling the Daesh group pushed closer to the Old City in the militant stronghold of Raqqa on Monday, a monitor said.

The Kurdish and Arab fighters of the Syrian Democratic Forces entered Raqqa for the first time almost a week ago, after months of battle to encircle the northern city.

In the east of the city, they hold the Al Meshleb neighbourhood, captured days after the operation inside the city began, and on Sunday they seized their first district in the west, Al Rumaniya.

On Monday, fighting was continuing on both fronts, with the SDF advancing quickly in the eastern neighbourhood of Al Senaa, which leads to the Old City of Raqqa, the Syrian Observatory for Human Rights monitor said.

"The SDF forces now control 70 per cent of Al Senaa" next to Al Meshleb, Observatory director Rami Abdel Rahman said.

"If they take Al Senaa it will be the most important advance in the battle for Raqqa because it brings them to the centre of the city where the most important Daesh positions are," said Abdel Rahman.

"When they have captured Al Senaa, the real battle will begin."

The fighting is expected to become more difficult as the SDF approaches the more densely populated centre of the city.

"This fight will be tough," SDF fighter Berkhdan Qamishli said on Sunday.

"As we get close to the city centre, we'll be fighting inside multi-storey buildings. Urban battles are tougher than fighting in villages, but we will fight until we control the whole city."

In the west of the city meanwhile, SDF forces were battling to enter Hatin, the neighbourhood next to Al Rumaniya, captured on Sunday. The SDF reported "fierce clashes between fighters and the terrorists" on the two fronts and said 23 Daesh members had been killed, without specifying in which neighbourhood or when.

An SDF source said that fighters had uncovered a series of tunnels dug by Daesh militants in Al Meshleb.

"We are moving carefully and cautiously to avoid the huge number of mines that Daesh has planted in the city," the source added.

An AFP correspondent inside the west of the city on Sunday said the approach was littered with mangled motorcycles and unexploded mortar rounds fired by Daesh.

Source: Khaleej Times