Pakistani officials say a suicide bomb blast at a crowded public park in the eastern city of Lahore Sunday evening killed at least 65 people and wounded at least 300 others.
Women and children are among the victims, said Salman Rafiq, a health adviser to the government of Punjab province. He said there were seriously wounded people among those taken to local hospitals.
Witnesses say a large number of Christian families celebrating Easter also were present in the Gulshan Iqbal park when the explosion occurred.
A spokesman for a breakaway faction of the Pakistani Taliban (Jamaatul Aurar) claimed responsibility for the bombing and said it specifically targeted Christians.
Less than two percent of Pakistan's population is Christian.
A spokesman for U.N. Secretary-General Ban Ki-moon said Ban has called for "the perpetrators of this appalling terrorist act to be brought swiftly to justice." He said the secretary-general has urged Pakistan "to do its utmost to put in place protective measures to ensure the personal security of all individuals, including religious minority communities living in the country."
The United States condemned "in the strongest terms" the attack in Lahore, calling it a "cowardly act in what has long been a scenic and placid park," a statement from National Security Council spokesman Ned Price said.
Watch: Protests in Islamabad Over Execution of Mumtaz Qadri
Meanwhile in Islamabad, thousands of Pakistanis marched through the streets of the capital city Sunday to protest last month’s hanging of a man charged with murdering a provincial governor.
The protesters, mostly activists of Islamic parties, rallied against the execution of Mumtaz Qadri who gunned down Punjab's governor, Salman Taseer, in 2011 because the slain politician had called for reforms in the country’s Islamic law against blasphemy.
Police used blockades and fired tear gas shells to disperse the crowd but failed to do so and the protesters were trying to reach to the parliament building. Several security personnel are reported wounded in clashes with demonstrators.
Protesters set fire to several vehicles, containers and terminals of a public transport bus service linking Islamabad with the neighboring Rawalpindi city. Witnesses say police personnel were running out of tear gas and rubber bullets in their bid to disperse the crowed, prompting the government to call in the the military late on Sunday to help in controlling the situation.
Army spokesman Lt. General Asim Bajwa said troops have also been deployed to secure the so-called Red Zone in Islamabad where parliament, the supreme court and other key government buildings as well as diplomatic missions are located.