A bomb tore through a busy market in Pakistan's tribal belt on Thursday, killing at least five people and wounding 11 others near the Afghan border, officials said.
The device exploded in Pasht bazaar of Salarzai in Bajaur district, one of the toughest battlegrounds in Pakistan's fight against a Taliban insurgency in the northwest.
"At least five people were killed and 11 others wounded," local government official Tariq Khan told AFP.
Nobody claimed the responsibility for the bombing, but the Taliban have carried out several attacks against Salarzai tribesmen for forming pro-government militias and supporting military operations.
According to an AFP tally, around 5,000 people have been killed in militant attacks across the country since July 2007, when government troops raided an extremist mosque in the capital Islamabad, sparking a bloody insurgency.
The military conducted major anti-Taliban offensives in Bajaur in August 2008 and February 2009, and has repeatedly declared the district secure.
But militants have still proved able to strike.
Pakistan has lost more than 3,000 soldiers in the fight against homegrown insurgents but has resisted US pressure to do more to eliminate havens used by those fighting the Americans in Afghanistan.