The blast took place in the Landi Kotal area of the Khyber tribal agency [Reuters]

At least 15 people have been killed in northwest Pakistan after an explosion on a truck carrying fuel bound for NATO forces in Afghanistan.

The blast took place overnight in the Landi Kotal area of the Khyber tribal agency, officials said on Saturday.

The victims of the explosion were mainly young people who had gathered to collect oil from the tanker, Shafeerullah Wazir, a local administration official, said.

"The oil tanker caught fire after a blast caused by a small bomb before dawn," he said. "Villagers from nearby houses rushed and started collecting oil coming out of the destroyed tanker after the fire had been extinguished.

"Suddenly the fire erupted again and at least 15 people, including five young boys who had been collecting oil in their buckets, were burnt to death."

Tankers 'bombed'

In a separate incident, 16 other vehicles and containers, also carrying supplies for NATO troops in Afghanistan, were destroyed at the nearby Torkham border crossing, Iqbal Khattak, another local administration official said.

"The vehicles caught fire after a blast in one of the tankers around midnight last night," he said.

Khattak said the blast appeared to have been caused by a remote-controlled device that had been planted under one of the vehicles.

"There were no casualties," Khattak told the AFP news agency.

The Abdullah Azam Brigade, a group allied to the Tehreek-e-Taliban Pakistan, has claimed responsibility for the attack, Al Jazeera's Kamal Hyder reported from the capital, Islamabad.

The Palestinian-born Abdullah Azam was once a teacher to Osama bin Laden, the former al-Qaeda leader, and has spent time in Afghanistan.

Our correspondent said all fuel supplies to NATO through Pakistan have been suspended temporarily due to security concerns.

The development came as Imran Khan, the leader of the Pakistan Tehreek-e-Insaf party, was due to hold a sit-in in the southern port city of Karachi, seeking to have all NATO supplies that travel through Pakistan blocked, in retaliation against US drone strikes in the country's tribal areas.