Assailants set off a powerful time bomb next to an army truck parked in a teeming outdoor market in southwestern Pakistan (search) on Friday, killing at least 11 people and injuring more than two dozen others, police and hospital officials said.

The bomb, hidden on a bicycle, blew out windows, shredded the truck's canvas cover and left blood and debris over a wide area of the market, said police chief Rehmat Ullah.

The dead included one soldier and 10 vendors and passers-by, Pervez Bhatti, a senior police official, told Pakistan's private Geo television. Several of the 27 injured people were in critical condition, he said.

Hours after the blast, a little-known group, the Baluchistan National Army (search), claimed responsibility, but said it never wanted to kill civilians.

"Our target was the army truck and the soldiers," said the group's spokesman, Mir Azad Baluch, in a telephone call to a journalist in Quetta.

He said their group was also behind previous similar attacks.

He warned it would "continue to target military personnel until the federal government abandons plans to set up news garrisons in Baluchistan, and gives the people of our province their due share from the resources."

Baluchistan has been hit by a series of low-level bombings in recent years, most of which have not caused any casualties and have been blamed on feuding tribesmen.

Baluch's group is opposed to plans to set up new Pakistan Army garrisons in the province and has been trying to pressure authorities to get more returns from natural gas extracted from their region.

President Gen. Pervez Musharraf said the blast was perpetrated by people "working against peace and development in the country," and called on security agencies to capture those responsible.

Quetta mayor Rahim Kakar blamed "nationalists who don't want to see progress in Baluchistan."

Television footage showed the bodies of two victims lying in the road, their faces covered by thick shawls. The injured were frantically loaded into ambulances as investigators inspected the site.

In addition to homegrown militants, there are signs Baluchistan has become a base for Taliban and Al Qaeda-linked fighters.

Since July, Pakistani authorities have rounded up dozens of terror suspects around the country, even as it wages a bloody military campaign against Al Qaeda along its lawless border with Afghanistan.

On Dec. 1, police and intelligence agents exchanged fire with two suspected Chechen militants hiding in a home on Quetta's outskirts. One suspect died and the other was arrested. Eleven policemen were injured when the men hurled grenades during the raid.

The city has also been rocked by sectarian violence.

In March, suspected Sunni militants fired at a Shiite procession here, killing 44 people and wounding 150. In July 2003, attackers with machine guns and grenades stormed a Shiite mosque in the city, killing 50 people praying inside.

Musharraf's counterterrorism efforts have made him a key ally of the West against religious extremism, but have drawn criticism at home from those uneasy over his strong ties with Washington.