Armed tribesmen demanding freedom for some prisoners in Afghanistan on Wednesday  kidnapped 40 passengers of a bus coming from Kabul in Pakistan's restive border region, before a tribal council secured their release.

The passengers of the "Pakistan-Afghanistan friendship bus" were taken away to an undisclosed location by the tribesmen. The kidnappers sought the release of certain

prisoners in Afghanistan in exchange for the passengers, officials in Khyber Agency said.

The political administration of Khyber Agency convened a grand council that negotiated with the kidnappers and secured the release of the passengers.

The council assured the abductors that Pakistani officials would hold talks with their Afghan counterparts to release the prisoners in Afghanistan, Dawn News channel reported.

The incident occurred even as senior officials of the NATO forces in Afghanistan were holding a meeting with Pakistan Army officials in the Landi Kotal cantonment to

discuss the bomb attack on tankers carrying oil for US-led troops in the neighbouring country two days ago.

Six bombs went off in a parking lot, killing two persons and destroying over 40 tankers. The NATO and Pakistan Army officials discussed measures to improve security in the area in the wake of the attack.