A suicide bomber struck a World Food Programme distribution centre in the restive Bajaur tribal region of northwest Pakistan on Saturday, killing at least 40 people and injuring 72 others.
A large number of people had gathered at the UN agency's food distribution centre when the attacker detonated a suicide vest. Officials were quoted by TV news channels as saying that 40 people were killed and 72 others injured.
Geo News channel claimed that the suicide attack was carried out by a woman though this could not be independently confirmed.
No group claimed responsibility for the attack. Authorities usually blame the Taliban for such bombings. The World Food Programme had set up the centre to distribute food aid to people affected or displaced by an anti-Taliban operation launched by security forces in Bajaur tribal agency.
The injured were taken to the region's state-run hospital, where authorities declared an emergency. Witnesses said security forces cordoned off the area and launched a search operation.
Reports said that up to 1,000 people received food every day at the distribution centre at Khar, the headquarters of Bajaur.
The security forces had launched a major ground and air offensive against the Tehrik-e-Taliban Pakistan in Bajaur in 2008. The army declared victory over the militants last year though today's suicide bombing demonstrated that they retained the capability to carry out attacks in the region.