A bomb has ripped through eight fuel tankers parked outside a US-led coalition base in southern Afghanistan and injured two drivers, officials and eyewitnesses say.

All the tankers were destroyed in Friday's blast and clouds of black smoke poured over the Kandahar airfield, the main base for the US-led forces in southern Afghanistan, before the fires were extinguished.

Afghan army commander General Mohammed Sarwar said a bomb was believed to have been hidden in one of the tankers. He said the two injured drivers had been taken to a hospital.

US military spokeswoman Sergeant Marina Evans confirmed that some fuel tankers had been hit by a blast and had caught alight, but said the tankers belonged to the Afghan army and had been driving past the base when one hit a landmine.

String of attacks

There has been a string of attacks on tankers contracted by the US-led forces to haul fuel to its bases from neighbouring Pakistan. Friday's was the biggest in months.

The blast came amid a major surge in violence by Taliban-led armed men that has left more than 1400 people dead in the past half.

Violence has risen sharply in and around Kandahar, a former Taliban stronghold, with four bombings in recent weeks and five medical aid workers killed on Wednesday as they were returning to the city after treating people at a nearby refugee camp.

PHOTO CAPTION

An Afghan policeman searches the boot of a vehicle at a police checkpost in Kandahar, September 16, 2005. (AFP)