Islamabad - A suicide bombing during a gathering in Pakistan's tribal region along the Afghan border Killed at least 15 people and injured more than four dozen on Friday, officials said.

The jirga, a meeting of hundreds of members of the Alikhel tribe was being held in Khadezai village of Orakzai district to raise a traditional army, or lashkar, against Taliban militants operating in the area.

"A young man sneaked into the gathering and blew himself up around at 04:30 pm (1030 GMT)," said a security official who spoke on condition of anonymity. "Fifteen people have so far been confirmed dead and more than 50 are wounded."

Pakistan's tribal region serves as a safe haven for al-Qaeda and Taliban militants launching cross-border attacks on US-led international forces in Afghanistan.

Pressed by Washington, Islamabad has recently launched offensives in some districts of the largely ungoverned tribal belt against the Islamic insurgents. It also encouraged local tribesmen to raise lashkars to oust militants from their regions.