Officials in northwest Pakistan say a bomb has killed at least 16 people and wounded more than 40.
Authorities say the marketplace explosion Monday happened near government offices in the town of Jamrud, part of the Khyber tribal district.
No group has claimed responsibility for the attack.
Khyber is home to various Islamic militant groups, including the Pakistani Taliban, which have waged a bloody insurgency against the government for several years.
People look at damaged vehicles after a bomb blast in the Pakistani tribal area of Khyber, December 17, 2012.
A man walks past a burning vehicle after a blast in Khyber, Pakistan, December 17, 2012.
A woman looks through a window while a man who was wounded in a bomb attack at Fauji Market lies at the Hayatabad hospital in Peshawar, Pakistan, December 17, 2012.
People stand near coffins of people killed in a bomb blast in the Pakistani tribal area of Khyber, December 17, 2012.
A paramilitary soldier holds a rocket-propelled grenade at the site of a bomb attack at Fauji Market in Peshawar in the Kyber tribal region, December 17, 2012.
Elsewhere Monday in Pakistan, officials say gunmen killed a provincial government spokesman and two police officers in the troubled southwestern city of Quetta.
Police say the attackers shot dead Khadim Hussain Noori and then shot the police who were pursuing them.
The civil servant was a Shiite Muslim, and officials say the attack in Baluchistan province may have been related to sectarian unrest.
Baluchistan has experienced a spike in sectarian killings the past year as Sunni Muslim extremists have targeted Shiites.
The province is also the scene of a decades-long insurgency by Baluch nationalists who demand greater autonomy and a larger share of the province's natural resources.