Without warning, a blast tore through the park, killing indiscriminately.
Because of the innocent setting, an unusually high number of those injured were women and children. But the attack, claimed by a splinter group of the Pakistani Taliban, intentionally targeted Christians, the perpetrators say.
The suicide blast, in the eastern Pakistan city of Lahore, killed at least 69 people, a local government spokesman told CNN.
More than 341 others were injured, according to Punjab government spokesperson Jehangir Awan.
It comes at a difficult time for Pakistan's Christians, some of whom were in the city's Gulshan Iqbal Park to celebrate the holiday Sunday evening, only to see their Easter Sunday fragment into terror and chaos.
The religious group makes up only 2% of the population, and tensions are high between them and a hardline Muslim core which wants to see a strict interpretation of Islamic law take precedence in Pakistan's legal system.
One witness, Danish, was at the amusement park with his two sisters. He recalled the moment that the explosion ripped apart the park, killing one of his sisters and seriously injuring the other.
"It was so crowded that there was even no way of entering it. We went to a canteen to have something to eat, when there was suddenly a big blast. Everyone panicked, running to all directions. Many of them were blocked at the gate of the park. Dead bodies can be found everywhere," he told reporters.
"My sister got wounded in the neck. The object hit her looks like a piece of hard iron, and it burnt her in the neck. She was also wounded in the chest."
Ehsanullah Ehsan, a spokesman for the splinter group of the Pakistani Taliban known as Jamat-ul-Ahrar vowed such attacks would continue. Parks in the city remained closed into Monday, for security reasons, according the deputy commissioner of police.
Pakistani Prime Minister Muhammad Nawaz Sharif strongly condemned the blast. Sharif was born in Lahore and enjoys strong support there.
Pakistan's internal terror operations took a new turn following the incident, with General Asim Bajwa tweeting that the Chief of Army Staff chaired a high-level meeting to review an operation in Punjab -- something that has previously resisted by Nawaz Sharif's government, which has its power base in the province.
The two main military operations that are ongoing are in the city of Karachi and in the northern tribal areas of North Waziristan.
Blasphemy law protests erupt
Protests erupted again Sunday, almost a month after a former bodyguard who assassinated a moderate politician was executed. Mumtaz Qadri, was hanged in a Rawalpindi prison February 29, five years after being found guilty of shooting and killing Punjab Gov. Salman Taseer.
The governor had spoken out against the blasphemy law that makes insulting Islam a crime punishable by death.
As many as 10,000 demonstrators gathered in the capital, Islamabad, Friday, praising Qadri and demanding changes to Pakistan's laws, including the adoption of Sharia law, according to local media reports
Indian Prime Minister Narendra Modi, who has worked to thaw the icy relations between the two neighbors, called Sharif on Sunday to express his grief over the bombing.
The Indian leader expressed solidarity with Pakistan, the Pakistani state-run news agency reported.
"Modi said coward terrorists had targeted females and kids which was highly condemnable and regrettable," according to the state-run agency, the Associated Press of Pakistan.
The United States and Australian governments also condemned the attack.
"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 in a statement.
Australian Foreign Minister Julie Bishop echoed the sentiment.
"As Christians worldwide celebrate Easter, a shocking terrorist attack in Lahore, Pakistan, reminds us that terrorism is a global scourge," she said Monday.
"The Australian Government condemns this horrific act that has killed dozens of civilians, including children, and expresses our condolences to the people of Pakistan and its government at this time."
History of violence
In March last year, suicide bombers attacked a Christian community,
also in Lahore, setting off two blasts that killed at least 14 people and wounded dozens more, officials said.
The Pakistani Taliban claimed responsibility for that attack too and warned of more to come.
The explosions, which struck the Nishtar Colony area in the city of Lahore, wounded at least 78 people, Dr. Muhammed Saeed Sohbin, medical superintendent at Lahore General Hospital, said then.
In 2013, suicide bombers struck a church
in the northwestern city of Peshawar, killing more than 80 people.