Alan Gomez

USA TODAY

A bomb blast in a park filled with Christian families celebrating Easter in the Pakistani city of Lahore killed 65 people and wounded hundreds more, a government official said Sunday.

A breakaway Taliban faction told the Associated Press that it was responsible for the explosion. Ahsanullah Ahsan, a spokesman for the militant group, Jamaat-ul-Ahrar, said it deliberately targeted Christians and warned of more attacks to follow.

Facebook check sent in error after Pakistan explosion

Salman Rafiq, a health adviser to the chief minister of Punjab province, said many of those injured were in critical condition and warned that the death toll could climb. Zaeem Qadri, a spokesman for the chief minister, said at least 300 were injured in addition to those killed.

The explosion took place near the children’s rides in Gulshan-e-Iqbal park, local police chief Haider Ashraf said. He said the explosion appeared to have been a suicide bombing, but the investigation is ongoing.

"Most of the dead and injured are women and children," Mustansar Feroz, the police superintendent of the area, told Reuters.

Pakistani Prime Minister Nawaz Sharif expressed grief and shock over the bombing, and Punjab Chief Minister Shahbaz Sharif declared three days of mourning starting Monday, according toThe International News, a Karachi-based newspaper. The prime minister on Sunday held a meeting to assess the security situation in Lahore, the government said.

Pakistan's army chief, Gen. Raheel Sharif, also convened an emergency meeting of the country's intelligence agencies to begin to track down those responsible for the attacks, said army spokesman Gen. Asim Saleem Bajwa.

In a statement, the Vatican said the attack "casts a shadow of sadness and anguish on the feast of the Easter. Once again cowardly, murderous hatred rages on the most defenseless."

In Washington, the White House condemned the bombing.

"This cowardly act in what has long been a scenic and placid park has killed dozens of innocent civilians and left scores injured," National Security Council spokesman Ned Price said. "We send our deepest condolences to the loves ones of those killed, just as our thoughts and prayers are with the many injured in the explosion. The United States stands with the people of Pakistan at this difficult hour."

Ashraf said the park was manned by police and private security guards. “We are in a war-like situation and there is always a general threat, but no specific threat alert was received for this place,” he said.

Footage broadcast on local television stations showed chaotic scenes in the park, with people running while carrying children and cradling the wounded in their laps.

"When the blast occurred, the flames were so high they reached above the trees and I saw bodies flying in the air," Hasan Imran, 30, told Reuters.

Nasreen Bibi waited at a nearby hospital for an update on the condition of her injured 2-year-old daughter.

"May God shower his wrath upon these attackers," she told Reuters. "What kind of people target little children in a park?"

After the attack, the Punjab government ordered all public parks, many of the city's main roads and several shopping areas closed.

Schools and businesses in the city will remain closed on Monday, the city's schools association and the Union of Lahore Traders said.

Sunday's bombing struck in the Punjab province where the prime minister was born and now serves as Sharif's political base. The region has long been more peaceful than other parts of Pakistan, which features constant skirmishes along its borders with Afghanistan and India. Critics have accused Nawaz of tolerating attacks in other parts of the country in exchange for keeping his province safe, a charge he strongly denies.

In recent years, Punjab has increasingly become a target.

In February 2015, five people were killed when a suicide bomber aligned with a Taliban splinter groups attacked a police complex in Lahore. The next month, attackers targeted two Christian churches in Lahore, killing more than a dozen, wounding 70 others and instigating protests from religious minorities who felt they were not being protected by the nation's government. And in August, a provincial minister and 16 others were killed when suicide bombers destroyed the minister's home, where he was holding meetings.

Contributing: Greg Toppo, USA TODAY