ALEPPO — Air strikes killed at least 46 people in opposition-held parts of Syria on Sunday, a monitor said, as government forces advanced in fierce clashes with rebels in east Aleppo.

Syria’s government is waging an offensive to recapture all of second city Aleppo, and it has so far captured more than 60 per cent of eastern districts that fell to rebels in 2012.

In Idlib province, in northwest Syria, at least 26 civilians were killed in strikes on the town of Kafr Nabel, the Britain-based Syrian Observatory for Human Rights monitor said.

An eyewitness said warplanes hit several places in the town, including a market.

The Observatory says it determines whose planes carry out raids according to their type, location, flight patterns and the munitions involved.

The group said 18 people were also killed in strikes on the town of Maaret al-Numan, where rescue workers and residents were trying to pull survivors from rubble at a market.

The monitor reported two additional deaths, one in an earlier strike on Maaret al-Numan and another in Al-Naqir, also in Idlib.

It said six civilians, four of them children, had been killed in a government barrel bomb attack on the town of Al-Tamanah in the same province.

Army advances in Aleppo

In east Aleppo, government forces advanced against rebels, taking three neighbourhoods and pushing into a fourth, state media and the Russian defence ministry said.

The army and allied forces are nearly three weeks into an operation to recapture all of the city, divided between regime and rebel forces since 2012.

Tens of thousands of civilians have fled the offensive, which has made steady gains and threatens to deal Syria’s opposition its worst defeat in the five-year civil war.

State television said late on Sunday the army had captured the districts of Karm al-Tahan and Myessar and advanced into the Qadi Askar neighbourhood.

The Russian defence ministry said government forces had also taken the district of Karm al-Katurji.

Rebels are increasingly under pressure in the remaining southeastern districts they control.

State news agency SANA said the air force was dropping leaflets over rebel-held areas urging "militants to abandon their weapons and... allow civilians and the sick and wounded to leave".

Damascus says rebels are preventing civilians from leaving the east and trying to use them as human shields.

But tens of thousands of residents have fled the east as the army has advanced, with some heading south to remaining rebel territory and others going to areas under government or Kurdish control.

The east has been pounded with air strikes, barrel bombs and artillery fire.

At least 311 civilians, including 42 children, have been killed in east Aleppo since the government assault began, the Observatory says. — AFP