BEIRUT — Dozens of fighters and civilians were killed in Syria's Idlib province as the government pressed a deadly offensive on Thursday toward a key town in the country's last rebel bastion.

The latest violence, which followed air strikes that killed 19 civilians on Wednesday, buried a cease-fire deal announced by Russia and rebel backer Turkey that never really took hold.

"Clashes broke out around midnight on Wednesday south of the city of Maaret Al-Numan, together with heavy bombardment despite the Russian-Turkish truce," Rami Abdel Rahman, head of the Syrian Observatory for Human Rights, said.

According to the Britain-based war monitor, the fighting raged in areas south of Maaret Al-Numan, the key target of the Syrian government's latest military offensive.

At least 26 anti-government fighters were killed, most of them members of Hayat Tahrir Al-Sham, a group that includes fighters from the former Al-Qaeda affiliate in Syria.

The Observatory said 29 government troops and allied militia were also killed in the fighting.

The Syrian state news agency SANA later reported that at least four civilians were killed by rocket fire on the city of Aleppo.

Jihadist and rebel groups are present west of northern city, on which hey routinely launch rocket attacks.

Abdel Rahman said that government forces were now just seven kilometers (less than five miles) from Maaret Al-Numan, a town that was one of the bastions of the uprising against President Bashar Assad's rule.

Nearly nine years into the conflict, protests against the government are still held in some of the province's towns.

In the city of Idlib itself, 19 civilians were killed and several others wounded in Russian and Syrian air strikes on Wednesday, the Observatory said.

Reporters saw scenes of chaos after the strikes, that blew several buildings in an industrial zone to smithereens.

The bombardment engulfed several vehicles, leaving torched corpses of motorists trapped inside.

Mustafa, who runs a repair shop in the area, was lucky to escape with his life. He had just left the store to pick up some spare parts.

He said he returned to find the shop destroyed and his four employees trapped under rubble. It was not immediately clear if they had survived.

"This is not the neighborhood I left two minutes ago!" Mustafa said, tears rolling down his face.

The ceasefire announced by the Russian army on Sunday joins a long list of short-lived or still-born initiatives to curb the violence in Syria.

"We live here without knowing if there is really a truce or if it's just in the media. On the ground, there is no truce. People are afraid, the markets are empty," Sari Bitar, a 32-year-old engineer living in Idlib city said on Thursday.

"Just like everybody else, I can't stay in an area on which the regime, Russian forces and Iranian militia will advance," he said.

"The only problem is that there is nowhere to go," Bitar said. "Syria is now limited to this geographical area, which is getting smaller day by day."

Assad has repeatedly pledged to continue the reconquest that Russia's 2015 military intervention kick-started until all Syrian territory has been reclaimed.

Idlib province is a dead end for people displaced from other formerly rebel-held parts of the country that government forces have retaken.

It has come under mounting bombardment in recent weeks, displacing tens of thousands of people in the northwestern province, which is home to some three million.

The United Nations' humanitarian coordination agency OCHA said that since Dec. 1 alone, almost 350,000 people had fled their homes, mainly heading northwards from southern Idlib, which has borne the brunt of the air strikes.

"An additional 650,000 people, the majority of them women and children, could be forced to flee their homes if the violence continues," the International Rescue Committee warned in a statement.

The European Union expressed deep concern over the collapse of the fledgling cease-fire in Idlib and also warned that further violence could trigger an unprecedented wave of refugees and displaced.

The winter conditions in Idlib, with sub-zero temperatures interspersed by heavy rain, are putting thousands of lives at risk.

A UN resolution on cross-border aid to Syria maintained two key entry points for UN humanitarian aid into Idlib, where the number of people in extreme need keeps growing. — AFP