Opposition activists and Syrian state media are reporting at least 13 people have been killed in fighting between government forces and insurgents in the northwestern part of Syria.

An uptick in violence has increasingly tested a Russia-Turkey sponsored truce in place since September that has averted a government offensive on insurgent-held Idlib and surrounding areas. The area is home to 3 million people.

The Syrian Observatory for Human Rights and first responders known as White Helmets say government shelling killed at least eight people Sunday in Saraqeb and Nairab towns in eastern Idlib.

A local hospital director, Maher Younis, told the state-run Ikhbariya TV that insurgents killed at least five people when they fired missiles at the government-held town of Massyaf in the adjacent Hama province.