Insurgents and NATO-led troops are engaged in a battle around Bagram airbase, the large NATO base near Afghanistan's capital, a NATO spokesman said on Wednesday, AP reported.
"There is an ongoing engagement with insurgents in the area of Bagram air field," Major Marcin Walczak told Reuters.
Bagram lies about an hour's drive north of Kabul and is one of the biggest military bases in Afghanistan, mainly holding U.S. troops.
The incident comes after the Taliban announced a spring offensive against the Afghan government, foreign forces and diplomats in Afghanistan in response to NATO plans for an offensive on the group's southern stronghold of Kandahar.
On Tuesday, a Taliban suicide car bomber attacked a NATO-led military convoy during rush hour in the Afghan capital on Tuesday, killing 12 Afghan civilians and six foreign troops, including five Americans.