Two explosions struck a paramilitary training centre in northwestern Pakistan on Friday, killing at least 68 people nearly all recruits in the bloodiest attack in the country since a US raid killed al-Qaida chief Osama bin Laden.
A suicide bomber detonated at least one of the blasts in the Shabqadar area of Charsadda district, police said.
Dozens of people also were wounded when the explosions went off at a main gate of the Frontier Constabulary training site, police official Nisar Khan said.
Many recruits were boarding vehicles to go home for a short break at the end of a recent training session.
No group immediately claimed responsibility. But militants have pledged to avenge bin Laden's May 2 killing, and many have been expecting reprisal strikes on Pakistani territory.
The September 11 mastermind and at least four others were killed by US Navy Seals who raided bin Laden's compound in Abbottabad, Pakistan, a garrison city. Bin Laden is believed to have lived in the large house for up to six years.
Pakistani officials have denied knowing he was there but have criticised the American raid ordered by President Barack Obama as a violation of their country's sovereignty.
Pakistani leaders have also repeatedly pointed out that tens of thousands of their own citizens have died in suicide and other attacks since September 11, 2001, when Islamabad became an ally of the US in taking on Islamist extremists.
Many of the attacks in Pakistan have targeted security forces, including young cadets or recruits.
