At least 14 law enforcement personnel were killed in western Syria overnight in an “ambush” by the former forces of deposed leader Bashar al-Assad, the interior ministry said on Thursday, in an indication of challenges for the country’s new government.

The attack in the countryside of the Tartus region also injured 10 officers, according to the ministry. It came hours after the new government’s military operations command said its forces killed “a besieged group of remnants of the former regime” in the same area.

The ambush is the first known large attack by Assad loyalists since his ouster less than three weeks ago, and adds to the tests for Syria’s new ruling administration, including protests by religious minorities concerned over their rights under an Islamist rule and a new Israeli military occupation of Syrian territory in the south.

The new authorities have set a deadline for former regime forces and gangs to hand over their weapons, less than three weeks after Assad fled the country as rebels advanced on the capital Damascus.