A car bomb exploded in a crowded market in Pakistan's troubled north-west tribal region near the Afghan border, killing 17 people and wounding more than 40 others, officials said.
The bombing apparently targeted the office of the assistant political agent for the Khyber tribal area, one of the top local government officials, said Hidayat Khan, who works in the office.
The office is located in Jamrud, the main town in the region.
The death toll is expected to rise, according to Rehman Shah, a government official in the north-west city of Peshawar. Twelve of those wounded by the explosion are in a critical condition, he said.
Local TV footage showed several cars badly damaged outside the office. Residents threw buckets of water on burning vehicles as rescue workers transported the wounded to the hospital.
No group immediately claimed responsibility for the bombing.
Khyber is home to various Islamist militant groups, including the Pakistani Taliban, which have waged a bloody insurgency against the government for the past few years.
The army has carried out offensives against the Taliban in most parts of the tribal region, including Khyber, but militants continue to carry out regular attacks in the country.
10 Taliban militants attacked the military side of an international airport in Peshawar on Saturday night with rockets and car bombs, killing four people and wounding over 40 others.
Five of the militants were killed during the attack, and five others died the next day in a gun battle with security forces.
Elsewhere, gunmen killed a provincial government spokesman in the south-west Pakistan in an apparent sectarian attack, and then shot two nearby policemen dead, police said.
The attackers shot Khadim Hussain Noori in Quetta, the capital of Baluchistan province, said local police official Hamid Shakeel. Mr Noori was the provincial spokesman and also a Shia Muslim.
As the gunmen were speeding away on a motorcycle, they killed two policemen and wounded a third, said Mr Shakeel.
Baluchistan has experienced a spike in sectarian killings in the past year as radical Sunni Muslims have targeted Shias, who they consider to be heretics.
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.