Syrian and Russian warplanes launched a series of airstrikes on Monday on areas taken over by rebels in north-west Syria during a surprise offensive, activists in Idlib and a war monitor said. According to the White Helmets,

Syrian and Russian jets are stepping up strikes on opposition forces in northern Syria in retaliation for the sudden offensive that has cost the regime control of the country’s second largest city, Aleppo.

Syrian and Russian air strikes killed at least 25 people across north-western Syria on Sunday, the White Helmets civil defence group said on Monday. The deaths were reported amid a second day of intense bombardment against a shock insurgency.

At least 25 people were killed in northwestern Syria in air strikes carried out by the Syrian government and Russia, the Syrian opposition-run rescue service known as the White Helmets said early on Monday.

At least 25 civilians, including 10 children and four women, were killed on Sunday in Russian and Syrian government airstrikes on the Syrian city of Idlib and rural Aleppo, the White Helmets announced Monday.

Russian and Syrian fighter jets have struck the rebel-held city of Idlib on Dec. 1 amid attempts to push back an insurgency that has taken over most of Aleppo, Reuters reported, citing Syrian army sources.

On Sunday, Russian and Syrian jets stepped up their bombing of northwestern Syria, targeting rebel-held areas, Reuters reports. According to Reuters, on December 1, aircraft from both nations struck the city of Idlib in northern Syria,