Syrian opposition activists say rebels have shot down a warplane in the country's northwest where government forces and their allies are advancing under the cover of intense airstrikes. They also claimed that they have captured the pilot.

The Britain-based Syrian Observatory for Human Rights says the warplane was downed on Saturday afternoon near the rebel-held town of Sarqeb, which Syrian troops have been trying to reach under the cover of Russian airstrikes.

The Observatory's chief Rami Abdurrahman says it's possible the warplane could be Russian. He added that the pilot ejected and landed alive on the ground.