ISLAMABAD, Pakistan -- Taliban attacks on election candidates in northwestern Pakistan killed at least eight people and wounded dozens on Sunday, adding to a growing toll of militant violence in the run-up to elections scheduled for May 11.
A bomb planted outside the office of a Shiite politician in the garrison city of Kohat killed five people, police officials said, while a second explosion near the office of a tribal candidate in the regional capital, Peshawar, killed at least three.
A Taliban spokesman, Ehsanullah Ehsan, claimed responsibility for the attacks. Neither candidate was wounded.
At least 50 people have died since early April in election-related attacks, mostly carried out by the Taliban, that have damaged public confidence in the elections and underscored the determination of militants to influence the results.
The bloodshed had been concentrated in northwest Khyber Pakhtunkhwa Province, where the Taliban have vowed to attack rallies organized by the secular-minded Awami National Party, but the violence has spread to other provinces in the past week.
In the port city of Karachi, at least 24 people have died since Tuesday in a series of bombings against the Awami Party and the Muttahida Qaumi Movement, another secular party that dominates the city's politics. Attacks in the city on Saturday killed six.
In northwestern Baluchistan Province, Baluch nationalists claimed responsibility for a bomb attack on a candidate from the opposition Pakistan Muslim League-Nawaz party that missed its target, Sardar Sanaullah Khan Zehri, but killed his son, brother and nephew.
Thousands of teachers in Baluchistan have refused to work at polling places because of militant threats, the newspaper Dawn reported Sunday.
Campaigning has been largely unaffected, however, in Punjab, Pakistan's most populous province, which is the stronghold of the opposition leader Nawaz Sharif who remains the favorite to become prime minister.
Large rallies in Punjab and the northwest by the former cricket star Imran Khan, who has advocated talking to the Taliban instead of fighting them, have also avoided attacks. At a rally on Saturday, Mr. Khan told supporters that "'the teachings of Sufism" would help combat the scourge of militancy.
The governing Pakistan People's Party, which has also been threatened by the Taliban, has largely escaped violence by scaling back its campaigning in the most dangerous areas.
Pakistan's military, which is conducting operations against the Taliban in the tribal belt, has kept a low profile during the surge in attacks on politicians, although it will provide security on Election Day.
Fears are growing that a major militant attack before May 11, particularly one targeting a major political leader, could have a destabilizing effect on the vote itself. Memories are fresh of the assassination of the opposition leader Benazir Bhutto weeks before the last election in 2008.
Sunday's attacks in the northwest were directed at independent candidates from the tribal belt. The police said they suspected that the Shiite candidate in Kohat could have been the target of sectarian extremists.
"As if providing security to our candidates from Peshawar was not enough, we now have to look after the tribal candidates," said Liaqat Khan, the city's police chief.
Ismail Khan contributed reporting from Peshawar, Pakistan.
This article originally appeared in The New York Times.