A Russia-backed regime offensive has displaced close to 700,000 people in northwest Syria since December, the United Nations said Monday, as bombardment by Damascus and Moscow killed 29 civilians in 24 hours.
Syrian government forces backed by Moscow have pressed a blistering assault against the last major rebel bastion in Syria's northwest for more than two months.
The violence in the provinces of Idlib and Aleppo has displaced 689,000 people, said David Swanson, spokesman for the United Nation's humanitarian coordination office, OCHA.
"The number of people being displaced in this crisis is now spiraling out of control," he told AFP.
The exodus is one of the largest of the nine-year civil war and risks creating one of the worst humanitarian catastrophes of the conflict.
It comes amid heightened bombardment by the regime and Russia which left 29 civilians dead in less than 24 hours.
Six children were among nine civilians killed early Monday in raids on the village of Abin Semaan, in Aleppo province where Russian-backed regime forces have been waging a fierce offensive to retake a key highway, said the Syrian Observatory for Human Rights.
At the site of the raids, a rescue worker carried out the body of a little girl in a thick woolen blanket, while one of her relatives pleaded for the body, said an AFP correspondent.
Volunteers shivering in near-freezing temperatures hacked away at mounds of rubble, rescuing a dust-covered man and a little child who had been trapped beneath.
The latest airstrikes follow a night of heavy bombardment by Russia and the regime that had already killed at least 20 civilians in the neighboring provinces of Idlib and Aleppo, according to the Observatory.
- Sleeping in the open -
Around half of Idlib province, along with slivers of neighboring Aleppo and Latakia provinces, is dominated by militants of the Hayat Tahrir al-Sham alliance and their rebel allies.
Some three million people, half of them already displaced at least once by violence elsewhere in Syria, live in the area.
Some 50,000 fighters are also in the shrinking pocket, many of them militants but the majority allied rebels, according to the Observatory.
The heightened attacks on the region come as pro-regime forces close in on a section of a key transport artery that has long been in their sights.
The M5 connects Damascus to second city Aleppo and is economically vital to the government after nine years of war.
Only a two-kilometer section of the highway remain outside government control after regime forces seized large swathes of it in Idlib and Aleppo in recent weeks.
The Syrian army said in a statement Sunday it had recaptured 600 square kilometers (230 square miles) in its latest push, comprising "dozens of villages and locations" in south Idlib and west Aleppo provinces.
Fleeing the army's advance, entire families have headed north in cars piled high with blankets, chairs, and pans as they seek to survive the winter.
But many are struggling to find shelter in the biting cold.
Displacement camps are at five times their capacity and the few available apartments are prohibitively expensive, forcing civilians to sleep in cars and open fields, aid groups and residents say.
- Turkish warnings -
The escalation in northwest Syria has sparked alarm from opposition backer Turkey which already hosts some 3.7 million Syrian refugees and fears another influx towards its border.
Since Friday, Turkey has shipped large convoys of vehicles carrying commandos, tanks, and howitzer artillery pieces to shore up 12 military posts it had set up in Idlib under a 2018 deal with Russia to stave off a regime offensive.
But the agreement has failed to stymie the government's advance, with Turkey saying regime forces have surrounded three of its outposts despite repeated warnings against such a move.
Turkish Defence Minister Hulusi Akar on Sunday said Ankara had other plans if agreements over the region continue to be violated.
"We have Plan B and Plan C," he said in an interview with the Hurriyet daily.
"We on every occasion say 'do not force us, otherwise our Plan B and Plan C are ready'."
He did not give details, but referred to Ankara's military campaigns in Syria since 2016.
Turkish President Recep Tayyip Erdogan has given Damascus until the end of the month to pull back from the outposts, and urged Russia to convince the regime to halt its offensive.
The warning came after eight Turks were killed last week by regime shelling, prompting a deadly response by the Turkish army.