At least eight people including five children were killed Tuesday (December 24th) in Russian airstrikes in north-west Syria, as France and Turkey appealed for an end to violence that has forced tens of thousands to flee.

Heightened regime and Russian bombardment has hit the extremist-held province of Idlib since mid-December, as regime forces make steady advances on the ground despite an August ceasefire and UN calls for a de-escalation.

Nearly 80 civilians have been killed by airstrikes and artillery attacks over the same period, according to the Syrian Observatory for Human Rights, which estimates that more than 40,000 people have been displaced in recent weeks.

"These attacks should come to an end immediately," Turkey said Tuesday after sending a delegation to Moscow to discuss the flare-up.

Turkey said Tuesday it was talking to Russia with the aim of reaching a new ceasefire to replace the August agreement.

"We are closely following the process for an end to the attacks, and these attacks should come to an end immediately and implemented under a new ceasefire," presidential spokesman Ibrahim Kalin told a televised news conference. "This is our main expectation from the Russian side."

The French foreign ministry called for "an immediate de-escalation".

"The military offensive by the Damascus regime and its allies is worsening the humanitarian crisis" in Idlib, it said in a statement.

Tuesday's strikes targeted the village of Jubass near the town of Saraqeb in southern Idlib, killing civilians sheltering in a school and nearby, said the Observatory.

The site of the attack was strewn with destroyed tents and smoking debris, said an AFP correspondent there.

Standing amid the wreckage, Hassan -- who has been living in the informal settlement -- said he was trying to leave when the attack happened.

"As we were packing the car, an airstrike hit us," he said.

Ground assault

The UN children's agency UNICEF on Tuesday condemned the violence in Syria's last major opposition bastion.

"Children are bearing the brunt of intensifying violence in north-west Syria," it said in a statement.

Since Thursday (December 19th), regime forces have taken control of dozens of towns and villages in southern Idlib following battles with extremists.

The clashes have killed 260 fighters on both sides, according to the Observatory.

Regime forces are now less than four kilometres from the strategic city of Maaret al-Numan, Observatory chief Rami Abdel Rahman said.

In a statement on Tuesday, the Syrian army said it has seized 320 square kilometres from its rivals in recent days.

Fearing further regime advances from the south, thousands of Maaret al-Numan residents have fled northwards towards the Turkish border.

"I did not expect to have to leave," said Abu Ahmad, poking his head out of the pick-up truck driving him and his family towards a camp for the displaced.

"This is my home, this is where I grew up," the father of 10 said.

Life-saving assistance

Idlib is dominated by the country's former al-Qaeda affiliate, extremist alliance Tahrir al-Sham.

Tahrir al-Sham chief Abu Mohammed al-Joulani said in a statement Tuesday that the war in Syria now is not against the regime alone anymore, but against its backers Russia and Iran who are pushing to occupy the country.

Idlib hosts some three million people, including many displaced by years of violence in other parts of Syria.

The latest spike in violence comes after Russia and China on Friday vetoed a UN Security Council resolution that would have extended for a year cross-border aid deliveries to four million Syrians, many of them in Idlib.

The move raised fears that vital UN-funded assistance could stop entering opposition-held parts of Syria from January unless an alternative agreement is reached.

France on Tuesday called on member states of the UN Security Council, namely Russia and China, to renew the resolution.

"It is more imperative than ever for the UN to maintain the most direct and effective access to populations in need through preserving cross-border assistance," the foreign ministry said in a statement.