A suicide bombing in Pakistan killed at least 52 people and injured more than 50 on Friday at a religious gathering to mark the birthday of Prophet Mohammed in a restive province bordering Afghanistan, health officials and police said.

No group has claimed responsibility for the blasts which come amid a surge in attacks by militant groups in Pakistan, raising the stakes for security forces ahead of national elections scheduled for January next year.

Hours after the suicide blast in Balochistan province, another blast ripped through a mosque in Khyber Pakhtunkhwa province which also borders Afghanistan, officials said, killing at least two people.

The mosque’s roof collapsed in the blast, local broadcaster Geo News reported, adding that about 30 to 40 people were trapped under the rubble.

Pakistan has seen a resurgence of attacks by Islamist militants since last year when a ceasefire broke down between the government and the Tehreek-e-Taliban Pakistan (TTP), an umbrella organisation of various hardline Sunni Islamist groups.

The TTP, which has carried out some of the bloodiest attacks inside Pakistan since its formation in 2007, denied that it had carried out Friday’s attack in Balochistan.

At least 58 people were wounded in the Balochistan blast, said Abdul Rasheed, a district health official, adding that the toll could rise as many people were in a serious condition.

Television footage of the attack’s aftermath showed hundreds of people helping the injured into ambulances.

“The bomber detonated himself near the vehicle of the Deputy Superintendent of Police,” Munir Ahmed, the deputy inspector general of police, told Reuters.

In July, more than 40 people were killed in a suicide bombing in northwestern Khyber Pakhtunkhwa province at a religious political party’s gathering.