Pakistani Taliban on Saturday claimed responsibility for the kidnap of more than 30 young people who mistakenly crossed the border from the country's lawless northwest into Afghanistan.

A spokesman for Tehreek-e-Taliban Pakistan's (TTP) said those kidnapped were not boys as reported by Pakistani officials but aged between 20 and 30, adding their fate would be decided by the central leadership of the organisation.

"We have kidnapped them. These people are with us, they are not kids but young people of ages between 20 to 30," Taliban spokesman Ehsanullah Ehsan told AFP by telephone from an undisclosed location.

"These people belong to the areas where tribesmen rose militias against TTP. We will thoroughly investigate about them and then our central leadership will decide their fate," Ehsan said.

Pakistani officials had said the incident took place on Thursday after a group of boys, aged between 12 and 18, left the Ghakhi area of Pakistan's Bajaur tribal region during celebrations marking the Muslim Eid holiday.

Bajaur administration official Islam Zeb said the boys had been abducted by a militant group allied with Taliban commander Maulvi Faqir Muhammad, who led local insurgents but is believed to have fled to Afghanistan in 2010.

Zeb told AFP on Saturday that a delegation of Pakistani tribesmen is negotiating with the tribal elders in Afghanistan "to put pressure on the kidnappers to set them free,".

"We are trying our best to seek their release. A tribal Jirga has been sent to Kunar for negotiations," Zeb said.

Malik Ayaz, a tribal elder involves in negotiations told AFP on Saturday that Pakistani tribesmen are facing difficulties securing the safe release of the abductees as the border area is mostly controlled by Taliban.

"We are in contact with the tribesmen across the border but at the moment we are facing difficulties in negotiations. This border area is largely controlled by Taliban," he said.

Mohammad Akhtar, a witness who managed to fleethe mass kidnap said dozens of young people were in the area.

"We were there to enjoy our Eid vacations and all of a sudden Taliban attacked," he said.

"Some people managed to flee the area because they were a little bit away from the attack site," he said.

"We were their just for fun and to see the mountainous areas and to enjoy," he added.

Afghan border police commander General Aminullah Amarkhel, the governor of Kunar, where the boys vanished, Fazlullah Wahidi, and the local Afghan Taliban commander all told AFP on Friday they were unaware of the incident.

Afghanistan shares a disputed and unmarked 2,400-kilometre (1,500-mile) border with Pakistan, and Taliban and other Al-Qaeda-linked militants have carved out strongholds on either side.

The Pakistani military has repeatedly claimed to have eliminated the militant threat in Bajaur, one of seven districts in the semi-autonomous tribal belt that the United States sees as the global headquarters of Al-Qaeda.