NW Syria violence displaces 500,000 in two months

"Since December 1, some 520,000 people have been displaced from their homes, the vast majority -- 80 per cent -- of them women and children," David Swanson, spokesman for the UN Office for the Coordination of Humanitarian Affairs, said.

The wave of displacement, which coincides with a biting winter, is one of the largest since the start of the Syrian war nearly nine years ago.

"This latest displacement compounds an already dire humanitarian situation on the ground, when over 400,000 people were displaced from the end of April through the end of August, many of them multiple times," Swanson said.

He said the UN was alarmed by the plight of more than three million people -- half of them displaced from their homes -- who live in Idlib province and surrounding areas.

Government troops and militia backed by Russian and other allied forces have in recent weeks ramped up the pressure on the last pocket still controlled by rebels and jihadists.

They have retaken dozens of villages and some major towns -- including the erstwhile rebel bastion of Maaret al-Numan -- and are pushing northwards, sending displaced populations ever closer to the Turkish border.