At least 40 people were killed and dozens more wounded yesterday when a bomb exploded during evening prayers at a public park in Karachi.

The bomb was detonated under a stage erected by a Sunni Muslim group at Nishtar Park in the largest Pakistani city. The gathering was a celebration of the birthday of the Prophet Muhammad.

“We don’t know who might be responsible, but we are handling a big tragedy,” Shah Nawaz, the area police chief, said.

Semi Jamali, a doctor at a nearby hospital, said that at least 24 people killed in the blast were brought to his facility, where dozens more were being treated for wounds. The bodies of eight more people killed in the attack were taken to another hospital, he added.

Scenes of mass confusion broke out after the explosion in the park, where hundreds had gathered for the service. Scores of men wearing white robes clambered on to the stage to attend to bloodied victims.

An angry mob burnt cars and pelted police officers with stones, but officers shot their firearms into the air to disperse the crowd. (AP)