At least 41 people have been killed in a suicide bombing in a northwestern Pakistani tribal area bordering Afghanistan, officials said.
The blast took place at a ration distribution point of the World Food Programme in Khar, the main town of lawless Bajaur tribal district.
"At least 41 people are dead and more than 60 wounded in suicide bombing," a tribal administration official Sohail Khan said.
Doctor Mohammad Hafeez, the head of the local state-run hospital, confirmed the death toll and said there were several women and children among the casualties.
Bajaur was once a stronghold of Taliban militants who have carried out several bombing and suicide attacks.
Pakistan's military first launched operations in Bajaur in August 2008 and have repeatedly claimed to have eliminated the Islamist militant threat.
The country's northwest tribal belt is a stronghold of homegrown Islamist militant groups and extremists who fled Afghanistan after the US-led invasion toppled the hardline Taliban regime in late 2001.
About 4,000 people have died in suicide and bomb attacks across Pakistan since government forces raided an extremist mosque in Islamabad in 2007. The attacks have been blamed on networks linked to the Taliban and al Qa'eda.
Bajaur is one of seven Pakistani tribal districts. The United States considers Pakistan's tribal belt the global headquarters of Al-Qaeda and the most dangerous place on Earth.
US officials are putting pressure on Pakistan to launch a major ground offensive in the tribal region of North Waziristan, considered a fortress for Taliban groups fighting US-led troops in Afghanistan.
Pakistan vehemently denies accusations that it is not doing enough to eradicate the Taliban in the northwest, saying 2,421 troops have been killed in fighting Islamist militants from 2002 until April this year.
Pakistan supported the Taliban regime in Afghanistan from 1996-2001, but became a US ally after the 9/11 attacks on New York and Washington by Al-Qaeda.