Taliban militants have unleashed a battery of suicide attacks since Pakistan launched a major offensive in the volatile Swat Valley in the country's northwest over a month ago. Friday's bombing of the cleric, Sarfraz Naeemi, at his seminary in the eastern city of Lahore triggered a wave of public anger and revulsion.
Thousands of people were expected to gather Saturday for his funeral in the country's cultural capital.
Police said the bombing was a targeted assassination. The cleric had recently condemned suicide attacks as un-Islamic and denounced the Taliban as murderers and "a stigma on Islam." He also threw his support behind the military operation in Swat.
Four others died and three were wounded in the attack. In its aftermath, hundreds of outraged seminary students shouted "Down with the Taliban!"
The seminary bombing was echoed within minutes at a mosque used by troops in the northwestern city of Nowshera, killing at least four and wounding 100. The attacks took the count of suicide bombings to five in eight days, including a huge blast at the luxury Pearl Continental Hotel in nearby Peshawar that killed 11 people, including U.N. workers.
Taliban commander Saeed Hafiz claimed responsibility for the blasts at the seminary, hotel and in Nowshera on behalf of Tehrik-i-Taliban, the group headed by Pakistani Taliban chief Baitullah Mehsud, local media reported.
Naeemi's son, Raghib, filed a criminal complaint Saturday accusing Mehsud of murder, conspiracy and terrorism, saying his father had been receiving threats for his outspoken views.
"Baitullah Mehsud is responsible for planning and motivating the attack that killed my father," police official Sohail Sukhera quoted the complaint as saying.
In his address early Saturday, Zardari said Pakistan was, "fighting a war with those who want to impose their agenda on this nation with force and power."
"These people murdered thousands of innocent people. By spreading terror in Pakistan and by scaring people, they want to take over the institutions of Pakistan. They do everything in the name of Islam, but they do not have anything to do with Islam. They are cruel. They are terrorists."
In Washington, U.S. defense officials said Friday that Pakistan was planning a new assault into the lawless tribal district of South Waziristan, where senior al-Qaida and Taliban leaders are believed to have strongholds.