A Taliban bomb attack on tankers carrying fuel to Nato forces sparked an inferno which consumed up to 24 lorries

Afghan drivers managed to save many trucks from the attack in Samangan province, but around two dozen were lost.

Sidiq Azizi, a provincial spokesman, said the explosion happened at around 2am and fire fighters spent hours trying to control the blaze.

"There was a big boom. It's possible that it was a magnetic bomb from insurgents," he told the AP news agency.

"I counted 20 fuel tankers burning. The weather is very hot and it's hard to get close to the fire."

The Taliban claimed responsibility for the bombing.

An influential MP and former militia commander was killed in the same province at the weekend when a suicide bomber struck his daughter's wedding.

The lorries were carrying fuel from Nato's northern logistics route, officials said, which sees fuel and supplies ferried across Russia and Central Asia into northern Afghanistan.

The route has grown significantly in importance this year as commanders have been forced to switch from the southern route via Pakistan.

Islamabad blocked that route in protest after an American helicopter killed 24 Pakistan soldiers during an accidental border clash.

Convoys travelling through Pakistan are often attacked by militants.

The northern route has been considered safer, though far more expensive.

A spokesman for the Nato-led coalition could not confirm that the fuel was headed to Nato bases.

He said: "Very early this morning a fuel truck parked in a large staging area along with dozens of other trucks was targeted with an improvised explosive device.

"The device went off, there was an explosion and subsequently Afghans in the area were able to remove most of them, with the exception of 24 trucks." Pakistan reopened the southern supply route earlier this month, though many haulage firms are reportedly awaiting compensation and security guarantees before resuming journeys from the port of Karachi to the Afghan border.