A suicide car bomb exploded near a NATO airbase in southern Afghanistan on Thursday, killing two civilians, wounding 15 others and injuring four foreign soldiers, police said. "The suicide bomber detonated his car as an ISAF convoy was entering the Kandahar airfield," Kandahar provincial police chief General Abdul Razeq told AFP.

"As a result of this suicide attack two civilians have been killed, and 15 civilians and four ISAF soldiers have been injured."

A spokesman for NATO's International Security Assistance Force confirmed the attack, without giving details of any ISAF casualties.

Last week, Taliban suicide attackers struck at a NATO base at Jalalabad airport in eastern Afghanistan, killing five people and wounding several foreign troops in a two-hour battle, officials said.

A total of eight attackers armed with rocket-propelled grenades and automatic weapons were killed, Afghan officials said.

Both assaults came as the summer fighting season should be drawing to a close, indicating that the insurgency remains resilient after surviving the biggest onslaught US-led forces will throw against them.

The last of the extra 33,000 soldiers President Barack Obama deployed in a "surge" nearly three years ago left in September, and the vast majority of the remaining NATO force of more than 100,000 will follow by the end of 2014.