Kabul  - US forces killed 12 militants after suspected Taliban insurgents shot down an American helicopter in central Afghanistan, the US military said Tuesday.

The incident happened Monday in the Sayed Abad district of Wardak province, 50 kilometres west of Kabul, when a rocket-propelled grenade hit the tail of the UH-60 Blackhawk helicopter, forcing it to the ground, the US military said in a statement.

The crew members on board returned fire and killed five militants, it said.

Seven other militants were killed and another one was detained when the US soldiers continued searching the area and were engaged by more militants, the statement said.

No coalition soldiers were killed in the attack and the helicopter was recovered and taken to a nearby military base, it added.

Taliban militants claimed responsibility for the attack but said all the soldiers aboard the helicopter were killed.

US-led coalition and NATO-commanded forces heavily rely on helicopters and warplanes as part of their fight against Taliban-led forces, who have increased their attacks recently.

In another incident, one militant was killed and seven others were detained by coalition forces in two separate operations Monday in the eastern provinces of Khost and Ghazni, a separate US military statement said.

More than 4,000 people - mostly insurgents - have been killed in the Afghan conflict so far this year. (dpa)