Five rockets were fired at the massive base in the Taliban's spiritual capital where NATO forces are preparing a series of offensives to wrest control of the province.

A number of NATO personnel and civilian workers were wounded and no insurgents managed to enter the base, the statement said.

The base was hit by three rockets. One struck a helicopter terminal used by foreign troops, wounding four foreigners, one hit a shopping area and another failed to hit any significant target.

The Taliban came close to the airfield and fired rockets. Helicopters hit back at them with gunfire.

That attack came a day after a suicide car bomber hit a NATO convoy in Kabul, killing 12 Afghan civilians and six foreign troops. It was the deadliest strike against foreign troops in the heavily guarded capital since September 2009, when six Italian soldiers were killed.

The Taliban announced an offensive from May 20 against the government, foreign forces and diplomats in Afghanistan in response to NATO's plans for an operation against the group's southern stronghold of Kandahar.