A top Pakistani Taliban commander is claiming responsibility for Monday's attack on a Shi'ite religious procession that killed 43 people and sparked fires that burned for days.
Asmatullah Shaheen said Wednesday his group sent the bomber who wreaked havoc on the Ashura ritual in the southern city of Karachi. He told Reuters news agency that the Taliban "will carry out more such attacks within ten days."
Monday's attack destroyed more than 500 shops along the procession route and sparked riots despite calls for calm by the Pakistani government.
Thousands of people in Karachi attended funerals for the victims on Tuesday, and some said they blame the government for failing to provide adequate security.
Pakistani President Asif Ali Zardari has accused the extremists of trying to make Pakistan's people "fight one another."
Sunni Muslim extremists, including the Taliban, regard Shi'ites as heretics. Shi'ites make up one-fifth of Pakistan's population, while Sunnis account for about 70 percent.
Monday's bomb attack in Karachi was the third in as many days targeting Ashura observances by Pakistani Shi'ites.
A small bomb went off in Karachi near a Shi'ite procession Saturday, wounding about 20 people. A day later, a suicide bomber killed 10 people at a Shi'ite mosque in the capital of Pakistani-controlled Kashmir, Muzaffarabad.
The Pakistani military has been mounting an offensive to oust militants from their strongholds in northwestern tribal regions. The militants have retaliated with bomb and shooting attacks across the country. Karachi had been largely spared from the violence.
Some information for this report was provided by AFP and Reuters.