A suicide bomber killed at least 38 people outside a public park in the eastern Pakistani city of Lahore on Sunday, rescue officials and police said, striking at the heart of Prime Minister Nawaz Sharif's political heartland of Punjab.
The blast occurred in the parking area of Gulshan-e-Iqbal Park, just outside the exit gate and a few feet (metres) away from children's swings.
Eyewitnesses said they saw body parts strewn across the parking lot once the dust had settled. The park was particularly busy on Sunday evening due to the Easter holiday weekend.
"At least 15 people have been killed in a blast outside Gulshan-e-Iqbal Park," Jam Sajjad Hussain, a rescue service spokesman, told Reuters, adding that more than 30 people had been injured and taken to various hospitals in the city.
Most of the injured were women and children, Hussain said.
Police said it was not yet clear whether the blast had been carried out by a suicide bomber or a remote-controlled devise.
"We cannot rule out that this was a suicide attack but things will be clear soon," Haider Ashraf DIG Operations Lahore said.
Pakistan, a nuclear-armed nation of 190 million people, is plagued by a Taliban insurgency, criminal gangs and sectarian violence. Punjab is its biggest and wealthiest province.
In 2014, Pakistan launched an offensive against Taliban and affiliated jihadist fighters in North Waziristan, seeking to deprive them of safe havens from which to launch attacks in both Pakistan and Afghanistan.
Punjab has traditionally been more peaceful than other parts of Pakistan. Sharif's opponents have accused him of tolerating militancy in return for peace in his province, a charge he strongly denies.
Last year, a bomb killed a popular Pakistani provincial minister and at least eight others when it destroyed the minister's home in Punjab.