At least eight civilians have been killed in a rocket attack by Syrian government forces on a school in Idlib province, the country's last major opposition stronghold.

The Syrian Observatory for Human Rights said on Wednesday that four children were among the dead after government forces shelled a part of the school that was turned into a shelter for the displaced.

Observatory head Rami Abdel Rahman said 16 people were also wounded, some critically.

The Observatory added that pro-government forces also targeted other areas in Idlib, including the town of Khan al-Subul in the southern countryside of the province.

The White Helmets, a group of volunteers who pull people from the rubble of buildings flattened in bombing raids, said the school - in the town of Sarmin - was packed with students and teachers at the time.

It also said that two of the victims were teachers.

With blood, terror, and death, Russia and regime forces rang in the #NewYearsDay for Syrians. Scenes from the horrific massacre committed by the regime forces after targeting a school in Sarmin City with internationally prohibited cluster bombs this morning. pic.twitter.com/c6m55zygV3 — The White Helmets (@SyriaCivilDef) January 1, 2020

Overnight, rebel factions bombed areas under government control in Sahl al-Ghab, located in Hama's northwestern countryside.

Since mid-December, Syrian and Russian forces have intensified their bombing campaign on southern Idlib despite an August ceasefire deal.

The region is controlled by the rebel group Hayat Tahrir al-Sham and is home to three million people.

235,000 flee their homes

Since 19 December, forces supporting the government of President Bashar al-Assad have seized dozens of towns and villages following clashes that have killed hundreds on both sides.

Last week, the UN's humanitarian agency OCHA said more than 235,000 people had fled their homes in Idlib since 12 December.

Syrians sleep in the open after fleeing Idlib offensive Read More »

The displacements have seen public buildings such as mosques, garages, wedding halls and schools turned into shelters, OCHA says.

The mass movement had also left the Maaret al-Numan region, one of Idlib's largest urban centres, "almost empty".

The government advances in the province have brought its forces less than four kilometres from Maaret al-Numan, in southern Idlib.

"People from Saraqab and its eastern countryside are now fleeing in anticipation of fighting directly affecting their communities next," the OCHA said.

Last year, a total of 11,215 fighters and civilians were killed in Syria, the Observatory reported.

Of those, 3,473 were civilians including 1,021 children, it said, adding that it was the least deadly years on record since the war began in 2011.