KARACHI, Pakistan — A suicide bomber and two other attackers set off explosions during crowded Friday prayers in a Shiite mosque in the southwestern city of Quetta, killing at least 44 worshipers and wounding about 65, officials said.
Several hundred Shiite protesters rampaged through the streets of Quetta, the capital of Baluchistan province, after the attack, burning cars and firing into the air. They were dispersed by paramilitary police. Authorities imposed a curfew.
Two of the three assailants were killed in the attack, and the third died later of his wounds, according to the officials.
The attackers apparently planned the assault to inflict maximum casualties. The mosque was crowded with hundreds of people on the Muslim holy day.
Brigadier Javed Chema, head of the Interior Ministry's National Crisis Management Group, said at least one of the attackers was a suicide bomber. Police said the assailants burst into the mosque firing automatic weapons and tossing grenades.
One man who was wounded in the assault, Ahmad Ali, told Associated Press that he saw two bombers in the mosque. He said one man blew himself up while another, who appeared to be planting a bomb, was shot by a security guard.
Mahmood Hussain, another witness, told Reuters that two men fired on worshipers before a third blew himself up.
There has been ongoing sectarian violence between the Sunni and Shiite Muslim communities in Quetta, including several recent attacks apparently aimed at the minority Hazara community, which is Shiite.
No group claimed responsibility for Friday's attack. But members of the Shiite community, which makes up about a third of Quetta's 1.2 million people, blamed Sunni extremists. Chema said authorities were investigating all possible motives.
Nadim Ahmad, a supervisor with a Quetta ambulance service, said residents of the city feared the attack would unleash a spiral of violent reprisals. After the mosque explosions, Shiites tried to burn down a Sunni seminary in Quetta, and 30 students suffered smoke inhalation.
Sectarian tensions in Quetta increased in recent weeks after two attacks: on June 8, a dozen Hazara police recruits were killed by two gunmen on motorcycles. A Hazara religious leader, Syed Niaz Hussain, was killed days earlier, also by a pair of gunmen on motorcycles.
In the southern city of Karachi in February, nine Shiites were shot dead outside a mosque by gunmen on motorcycles.
President Pervez Musharraf has tried to reduce extremist activities by banning some militant Sunni and Shiite groups. Seeking aid and international support, Musharraf recently met with President Bush and British Prime Minister Tony Blair on an international tour.
Nearing the end of the trip in Paris on Friday, Musharraf promised tough action to find and punish the attackers.
"I don't know the details of this explosion or who did it. We have to act very strongly against them," he told reporters.
Special correspondent Ur-Rahman reported from Karachi and staff writer Dixon from Kabul, Afghanistan. Times wire services contributed to this report.