The UN said Tuesday that tens of thousands of people have fled new regime offensives in Syria, as Russian air strikes were reported to have killed 370 people, many of them civilians.

The Britain-based Syrian Observatory for Human Rights also said tens of thousands were fleeing the new fronts, and estimated that up to 100,000 had left their homes in Hama, Aleppo and Latakia provinces.

The mass displacement mostly took place south of Aleppo, one of the areas where regime troops have launched renewed attacks since Russia began to support them from the air on September 30.

“Around 35,000 people are reported to have been displaced from… the southwestern outskirts of Aleppo city, following government offensives over the last few days,” said Vanessa Huguenin, spokeswoman for the UN Office for the Coordination of Humanitarian Affairs (OCHA).

According to AFP, she said many of the refugees were living with host families and in “informal settlements” in the west of the province.

“People urgently need food and basic household and shelter items,” she added.

“Aid agencies are growing more and more concerned for families living outdoors as the weather is getting colder, especially overnight.”

Syria’s conflict has left more than 250,000 dead and forced millions from their homes since March 2011. A mass migration of refugees has resulted, inundating Europe.

Russia has carried out more than 500 air raids in support of strongman Bashar al-Assad’s forces, and according to an estimate published Tuesday by the Observatory for Human Rights, at least 370 people had been killed, including more than 120 civilians.

AFP contributed to this report.