Nine people were killed and eight others injured in an explosion at a cocaine laboratory on Colombia’s Pacific coast, police said on Friday. The incident occurred in the country’s southwestern Nariño department, an area known for cocaine production and home to the indigenous Awa community. Several armed groups are active in the region.

Authorities reported that the victims worked for the National Coordinator Bolivarian Army, a dissident faction of the former rebel group FARC. Preliminary investigations indicated that a gas cylinder exploded during drug production, triggering the blast. The rebel group also confirmed in a statement that improper handling of the cylinder caused the fire that engulfed the lab within seconds.

The group had rejected FARC’s 2016 peace agreement but is currently engaged in talks with President Gustavo Petro’s leftist government. The explosion site has long been part of a major cocaine trafficking route to the United States, where local smugglers operate with support from Mexican cartels.