Kabul - A joint patrol of Afghan and US-led coalition troops killed two Afghan policemen after they opened fire on the combined forces during an anti-insurgent operation in eastern Afghanistan, the military said Sunday.

Members of Afghan and coalition forces were conducting a ground operation in the north-eastern province of Kapisa on Friday night to "disrupt Taliban senior leadership and suicide attack networks" when they came under fire by several individuals, the US military said in a statement.

Knowing a police check post was nearby, the combined forces used various methods to identify themselves as a friendly force, the statement said, adding that despite several efforts, the police forces fired on the patrol.

"In self-defence, the patrol returned fire, killing two individuals," it said.

"We sincerely regret the loss of life of our friendly forces and we are continually working with our Afghan partners to prevent situations like this from happening in the future," Colonel Greg Julian, a US military spokesman said in the statement.

In the past seven years, dozens of Afghan police officers and army soldiers have been killed after NATO and coalition forces mistook them for Taliban insurgents. (dpa)