Intense fighting between pro-government forces and jihadist-led fighters in Syria’s Idlib province killed at least 39 fighters overnight, a war monitor said Thursday.

The violence, which saw air strikes, shelling and ground combat, further buried a ceasefire announced by Russia on Sunday in Idlib, the last major opposition bastion in the country.

Government and allied forces took two villages in their advance towards the key town of Maaret al-Numan, the Syrian Observatory for Human Rights said.