ISLAMABAD, Pakistan — Tens of thousands of troops fanned out across Pakistan today to bolster security ahead of next week’s parliamentary elections, but senior military officials said they would not try to interfere with the vote.

Underscoring concerns that violence could mar the election, at least nine people were wounded today in a bomb blast near the office of a candidate in the southwestern province of Baluchistan. It was the latest in a string of attacks that have overshadowed the campaign.

“The bomb was planted in a bicycle parked near the election office where Sardar Aslam Bizenjo was preparing to address a press conference,” said Hamid Shakeel, the police chief in Khuzdar, 185 miles south of Quetta.

The candidate was unhurt and there were no immediate claims of responsibility.

There are concerns that militants could launch attacks during the Feb. 18 vote, seen as key to Pakistan’s transition to democracy after eight years of military rule under President Pervez Musharraf, a key U.S. ally in the war against terrorism.

But the main fear is a major outbreak of political violence if there are allegations of vote rigging.

Interior Ministry spokesman, Jawed Iqbal Cheema said provincial officials had asked for the troops to help maintain peace and order during the election, but promised that none would be stationed at voting stations — a move which could serve to intimidate voters.

“We want to make sure people can cast their vote without any fear,” he said. “Nobody will be allowed to disrupt the polling process ... Anyone who tries to do so will be dealt with sternly.”

Though the army would not reveal numbers, Arif Ahmad Khan, the home secretary in the southern province of Sindh, said around 24,000 soldiers would patrol streets in his area alone.

“We do not want to reach a point where we have to say the situation is out of our control,” he said.

In Baluchistan and the North West Frontier Province, security forces would be placed on standby, responding only if violence flared, officials there said.

Army chief Gen. Ashfaq Kayani has sought to refocus the military away from politics since he took over the top job last November when Musharraf resigned gave up the post.

Over the weekend, dozens of people were killed in a suicide bombing and an attack Monday wounded a candidate while he was campaigning.

Security forces also were searching for Pakistan’s ambassador to Afghanistan, who was missing and feared kidnapped as he traveled in a volatile Pakistani tribal region.

The security threat has heightened at a time when public support for Musharraf has plunged to an all-time low. Opposition parties loyal to the late Benazir Bhutto and former Prime Minister Nawaz Sharif appear poised for a landslide victory, recent polls showed.

Musharraf is not a candidate but needs commanding majority in the new parliament to block any moves to impeach him.