Rebels raid Idlib in northwest Syria

Rebels entered neighbourhoods in the regime-held city of Idlib in northwest Syria for the first time in four days of fierce clashes with government forces, a monitor reported. 

"The armed groups have entered a number of areas inside the city and clashed violently with regime soldiers," said Rami Abdel Rahman, head of the Britain-based Syrian Observatory for Human Rights.

He said the fighters had advanced significantly from the northwestern and southeastern sides of the city, and that the total death toll since Tuesday was 117.

The city is almost completely encircled by rebel groups, leaving only two exit routes for pro-government forces.

An activist from the area said civilians were trapped in their homes. 

"The humanitarian situation is very difficult. There are refugees from other parts of the country who are in Idlib," said Ibrahim al-Idlibi.

On Tuesday, a new coalition of rebels launched a coordinated attack against Idlib.

Calling itself "the Army of Conquest", the coalition is led by al-Qaeda affiliate the al-Nusra Front and includes several other groups.

The rebels have advanced using "street fighting", Khaled Dhanoun, who is in contact with rebels in Idlib, told AFP.

On Thursday, Reuters reported that the Islamic Front, one of the alliances involved in the operation, had posted YouTube videos of battlefield developments. The footage showed fighters wearing camouflage and running through olive groves.

The front's Twitter account said a top military leader in Ahrar al-Sham - one of the main militias in the alliance - had been killed during the offensive, the Reuters report said.

According to Abdel Rahman, the Syrian army had sent in reinforcements and carried out airstrikes on rebel positions on the outskirts of Idlib.

The province of the same name borders Turkey and is largely under the control of al-Nusra, but the provincial capital, Idlib, remains in government hands.

Idlib is located near the main strategic highway that links Damascus and Aleppo.

If it falls to rebel groups, it would be only the second provincial capital lost by the government after Raqqa, which is now the de facto capital of the Islamic State group.

Since Syria's conflict began in March 2011, more than 215,000 people have been killed and around half the country's population has been displaced.