PESHAWAR - A bomb blast ripped through a busy market selling second-hand cars in a Pakistan`s infamous tribal district of Khyber on Friday, killing at least six civilians, officials said.

The explosion rocked Kuki Khel town in Khyber, on the NATO supply route into Afghanistan and part of Pakistan`s tribal belt that Washington considers an Al-Qaeda headquarters and the most dangerous region on Earth.

"At least six people were killed and another 16 wounded in the explosion," a senior local administration official, Rehan Gul Khattak, told AFP.

The timed device was planted in a ditch in a crowded market where people sell and purchase second-hand cars, he said.

Top Khyber administration official, Shafeerullah Khan also confirmed that the nature of the attack and casualties.

Officials described the area as a stronghold of Lashkar-e-Islam, a homegrown militant group that has carried out Islamist vigilante-style campaigns, kidnappings, shootings and attacks in Khyber.

The group has been the target of Pakistani military operations.

Bombs and attacks blamed on Taliban and Al-Qaeda-linked militants have killed more than 3,500 people across nuclear-armed Pakistan since government troops besieged a radical mosque in Islamabad in July 2007.

BDST: 1453 HRS, July 16, 2010