Taliban militants have kidnapped more than 30 Pakistani boys who had mistakenly crossed the unmarked border in the country's lawless northwest into Afghanistan, officials said on Friday.
They said the incident took place on Thursday after the group of boys, aged between 12 and 18-years-old, visited the area of Gharkhi in Pakistan's Bajaur tribal region for celebrations marking the Muslim Eid holiday.
"These boys inadvertently crossed into Afghanistan while picnicking on the second day of Eid and were kidnapped by militants," senior local administration official Syed Nasim told AFP.
However, Afghan border police commander General Aminullah Amarkhel said he had no knowledge of the abduction, and the local Taliban commander in Kunar province, where the boys vanished, also said he was 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.
Another Pakistani administration official speaking anonymously said security forces were stretched thin along parts of the frontier.
"It is a porous border and security cover is not available everywhere," he said.
Two local intelligence officials said that the kidnappers were apparently from a militant group allied with Taliban commander Maulvi Faqir Muhammad, who led insurgents in Bajaur but is believed to have fled to Afghanistan in 2010.
"The kidnappers were Taliban militants, belonging to Maulvi Faqir Muhammad group," one official said, on condition of anonymity.
The Pakistani military launched an anti-Taliban offensive in the area in 2008 and has repeatedly claimed to have eliminated the militant threat in Bajaur, one of seven districts in the country's semi-autonomous tribal belt that the United States sees as the global headquarters of Al-Qaeda.
Afghanistan and Pakistan blame each other for several recent cross-border attacks that have killed dozens and forced widespread displacement.
The Pakistani military have accused Faqir Muhammad of being behind an attack on a Pakistani paramilitary checkpost last week, which killed 25 troops.
It said his group helped co-ordinate the raid, adding that the terrorists regrouped in the Afghan provinces of Kunar and Nuristan with Afghan support after their expulsion from Pakistan.
For years the neighbours have traded accusations over the Taliban and Al-Qaeda-linked militants embedded in both countries, who criss-cross the porous, unmarked border and fight security forces from both governments.
But the escalating border war is fanning tensions at a key juncture as Afghans and Americans reach out to the Taliban for peace talks.
US troops in Afghanistan earlier this year abandoned remote outposts in the far reaches of Kunar and Nuristan provinces, where they had failed to win over locals, in favour of concentrating on larger population centres.