PESHAWAR: A bomb hidden in a vehicle exploded at a petrol station in northwest Pakistan Monday, killing seven people including three children in a strike claimed by Taliban militants, police said.

The blast hit on the outskirts of Charsadda town, about 30 kilometres (18 miles) northeast of Peshawar, the capital of the troubled North West Frontier Province which has seen a wave of suicide bombings and attacks this year.

Safwat Ghyur, a senior police official from Peshawar, told reporters that three young boys, two women and a male driver who were sitting in the vehicle were killed in the blast. Hospital officials put the injured toll at 10.

"It was a timed device. Somebody gave baggage to a passenger and the device was hidden in that baggage," Ghyur said in remarks broadcast on local TV.

District police chief Mohammad Riaz Khan told AFP that the bomb was planted in a pick-up truck carrying about 20 people, and said that one of the injured men later died on his way to hospital, taking the death toll to seven.

Eyewitness Ali Rehman told AFP by telephone from the scene that he had been travelling in the doomed vehicle, but stepped away for a drink.

"I was sitting in the open portion of the vehicle when it stopped for refueling. I went to drink a glass of water, and then there was a huge blast. I fell on the ground," he said.

"I see blood and body parts everywhere. Pieces of flesh are scattered on the ground."

Charsadda district borders the tribal region of Mohmand, where the government has tenuous control and Taliban militants are active.

The vehicle was headed to Mohmand when it blew up, and surviving passengers said they were from the district's Ambar village, where local tribesmen had raised a militia to fight against Islamist extremists.

A Taliban commander in Mohmand called an AFP reporter in Peshawar and claimed responsibility for the bombing.

"Our target was the lashkar (militia) people. The people sitting in the vehicle were from Ambar. These people attacked Taliban," said Qari Shakeel from an undisclosed location.

Police would not immediately comment on the motives for the blast.

Pakistan's military launched a series of offensives against Taliban militants in the northwest in late April prompting a string of revenge attacks, but there had been a lull in deadly bombings in the past month.

More than 2,000 people have died in Taliban-linked bombings in Pakistan since July 2007, including at least nine who were killed in a devastating attack on Peshawar's five-star Pearl Continental hotel in early June.