The bombing, the second this week, targeted several thousand Sunni Muslims as they departed from an overnight ceremony to mark the first anniversary of the shooting of Sunni Muslim radical leader, Azam Tariq, head of the outlawed radical group Sipah-e-Sahaba.
Information Minister Sheikh Rashid Ahmed said it could have been a sectarian act of revenge for a suicide bomber who killed 30 people at a minority Shiite Muslim mosque in the eastern city of Sialkot earlier this week.
But in a bid to prevent a spiral of revenge attacks, Interior Minister Aftab Ahmed Khan Sherpao labeled the bombing a terrorist act with "no relevance to the sectarian divide." He said, "I do not see the involvement of any religious group."
Sherpao also said he would advise provincial governments to ban religious gatherings, except for those at mosques, adding that no banned militant groups would be allowed to continue their activities. The minister had cautioned provincial governments to be on the alert for attacks during Friday prayers, which have become a traditional time for militant bomb attacks on mosques.
Police officials said a 15-pound bomb was planted in a car idling by the roadside near the site of the overnight gathering in a residential neighborhood. The bomb was probably detonated by remote control. As a result of the first explosion a transformer blew up causing a second blast. Electricity to adjoining areas was disconnected. Large patches of blood stained the ground and pieces of flesh lay scattered around. Nearby shops and homes were damaged.
Violence between Sunnis and Shiites in Pakistan has spiked in recent years, and Multan has become a hotbed of such sectarian attacks. Shiites make up about 20 percent of Pakistan's population while Sunnis make up 77 percent. There is generally little tension between the groups and a tiny minority of extremists is believed to be responsible for the sectarian violence.
Three thousand troops were sent to Multan as angry mourners gathered outside the Nishtar Hospital to collect bodies for burial chanted, "Infidels, infidels, Shia infidels."
Sipah-e-Sahaba, one of seven militant groups Pakistani President Pervez Musharraf outlawed after he joined the post-9/11 U.S.-led war on terror, blamed the Shiites and Musharraf for the attack.
The head of Sipah-e-Sahaba, which renamed itself Millat-e-Islamia after the ban, appealed to his followers to stay calm, and demanded the government track down those responsible within a week or he would call for a march on Islamabad, according to Reuters.
Abdul Jalil Naqvi, a leader of the main Shiite militant group, the banned Islami Tehrik Pakistan, denied those charges. He called it a terrorist act aimed at inciting sectarian war.