(CNN) -- Six members of mine-removal team were killed and three others were abducted following an ambush by gunmen in western Afghanistan on Thursday, a police official said.
The attack took place as the team was traveling to work in the Kohsan district of Herat province.
All of them worked for the HALO Trust, a UK-based mine clearance agency, according to Abdul Rauf Ahmadi, a spokesman for Herat's police chief.
The organization has 150 mine defusing teams and employs more than 3,000 Afghans, it says on its website. It also destroys other munitions.
Since the Soviet Union invaded Afghanistan in 1979, multiple warring parties have laid landmines, bringing the total number of mines to as many as 640,000, Halo Trust reports.
Afghanistan is one of the most-mined countries in the world, according to HALO.
In January, armed men abducted 68 members of another landmine-removal team.