Updated at 11:14 p.m. ET
Three bombs ripped through a Shiite Muslim religious procession in the eastern Pakistani city of Lahore on Wednesday, killing 25 people and wounding about 150 others, officials said.
The explosions appeared to be the latest in a string of attacks by Sunni extremists against the minority Shiites they consider infidels. Allied with al Qaeda and the Taliban, the bombers are also seeking to destabilize Pakistan's U.S.-backed government.
A Pakistani intelligence official told CBS News that investigators were focusing their attention on a hard-line group based in the Punjab, known to be loyal to the Taliban. The group, known as Lashkar-e-Jhangvi, is suspected by Pakistani intelligence officials for having carried out a number of previous terrorist attacks in the country.
"We are looking at Lashkar-e-Jhangvi as our prime suspect. The circumstances of the attack and the history are such that lashkar-e-jhangvi are the suspects," the official said on condition of anonymity.
The blasts were the first major attacks since Pakistan was hit by devastating floods more than a month ago. Lahore, the country's political capital and home to much of its military elite, has been regularly targeted by militants over the past two years.
The bombs exploded at three separate sites Wednesday evening as 35,000 Shiites marched through the streets of Lahore in their traditional mourning procession for the caliph Ali, one of Shiite Islam's most respected holy men.
The attack was a powerful reminder of the bloody split between hard-line groups among Pakistan's majority Sunni Muslim population, who have campaigned for years against members of the Shiite minority. Lashkar-e-Jhangvi falls among groups which in the past have campaigned for Shiite Muslims to be declared as heretics, reports CBS News' Farhan Bokhari.
Prime Minister Yousuf Raza Gilani condemned the blasts in a statement and said the attackers would not escape justice.
After the blasts, the marchers erupted in fury, setting fire to a police station, another police facility, two police cars and three motorcycles, said Zulfiqar Hameed, a senior police officer. Police lobbed tear gas canisters at the crowd and fired shots in the air to disperse the assailants, he said.
The first blast was a time bomb that exploded in the street near a well-known Shiite building, Hameed said. Footage of that explosion shown on Geo television showed a small blast erupting amid a crowd of people on the street followed by a large plume of smoke. Hundreds of people fled from the blast, while others rushed to carry the wounded to safety.
Minutes later, with the streets in chaos, a male suicide bomber who appeared about 18 years old tried to force his way into an area where food was being prepared for the marchers to break the traditional Ramadan fast and exploded, Hameed said. Soon after, another suicide bomber detonated himself at an intersection near the end of the procession.
Abbas Kumaili, a prominent Shiite scholar as well as a senator, called for three days of mourning over the attack and lashed out at the bombers.
"They are our enemies, both Shiites and Sunnis should remain united and foil their evil designs," he said.
The blasts killed 25 people and wounded about 150 others, said Sajjad Bhutta, a top local government official.
Hours earlier, three people were wounded in a shooting near a similar Shiite procession in the southern city of Karachi, but senior police officer Iqbal Mahmood said the incident did not target the march.
Islamist extremists have a history of attacking Shiites, non-Muslims and others they deem unacceptable.
In July, twin suicide attacks at Pakistan's most popular Sufi shrine killed 42 people. Another suicide bomber wounded eight worshippers at a Shiite mosque in eastern Pakistan.
Meanwhile, a bomb exploded near a police vehicle in the town of Shabqadar in northwest Pakistan, killing one passer-by and wounding 15 people including one police officer, police officer Nisar Khan said.
The bombings came after Pakistan army jets and helicopters targeted militant hide-outs near the Afghan border, killing 60 people identified as insurgents or their family members, including children, said security officials and a witness.
The attacks occurred Tuesday and Wednesday in different parts of the region.
There was no independent confirmation of the casualty figures because the area is too dangerous for outsiders to visit.
The raids Tuesday took place in several villages in Teerah Valley in the Khyber region and killed 45 people, the officials said. One official said some vehicles rigged with explosives had also been destroyed. He could not say how many.
He described the dead as insurgents, but said it was possible that people living with them could also have been killed. Separately, an intelligence officer said some women and children had been killed in the attacks.
Jihad Gul, who lives near one of the villages, said he had seen the bodies of at least 20 women and children.
Army spokesman Maj. Gen. Athar Abbas said reports of civilian casualties were unconfirmed.
The security officials spoke on condition of anonymity because they were not authorized to speak to the media.
An air attack Wednesday in the adjoining district of Orakzai killed 15 suspected militants and wounded 10 others, according to local government official Jamil Khan and a brief army statement.
Pakistan's army has been fighting Islamist militants in different parts of the northwest for more than two years.
Militants who fled major operations in the South Waziristan and Orakzai tribal regions are believed to have set up new bases in Khyber, about 60 miles northwest of the main city in the region, Peshawar.