KUNDUZ: Five aid workers, including two Western female doctors who were seized by gunmen last month in the remote mountains of northeastern Afghanistan, were freed in an operation, an Afghan official said on Saturday.

The aid workers employed by Swiss-based Medair were en route to flood-stricken parts of Badakhshan province in May when they were kidnapped.

“It was a successful operation conducted by troops and all five aid workers have been released,” said Shamsul Rahman Shams, the deputy governor of Badakhshan.

He said five hostage-takers were killed in the operation late on Friday. Police earlier said the men were demanding money for the release of the aid workers.

The kidnapping of foreigners has become relatively common in parts of Afghanistan since US-backed Afghan forces toppled the Taliban government in 2001, heralding a 10-year anti-insurgent war.

In 2010, 10 foreign medical workers, including six Americans, were killed in Badakhshan in an attack blamed on insurgents.

Police in Badakhshan said the gunmen in the latest incident belonged to criminal groups who were taking advantage of the difficult terrain and the loose grip that Afghan security forces have on the area.

The aid workers had been traveling by donkey to visit a clinic in the remote Yawan district, where the road had been destroyed by floods caused by melting snow after one of the worst Afghan winters in decades.

Afghan forces have taken over security in the provincial capital Faizabad and some parts of Badakhshan ahead of the withdrawal of Western combat forces in 2014.