Maj. Gen. Asif Ghafoor, a military spokesman, linked the attacks to alleged militant sanctuaries in neighboring Afghanistan and promised greater border security.

The death toll from twin blasts in the northwestern town of Parachinar climbed to 55 overnight, bringing the overall death toll from three separate attacks in Pakistan on Friday to 73, with several others in critical condition, officials said.

Shahid Khan, a government official in Parachinar, confirmed the toll on Saturday, saying residents who had been preparing to celebrate the end of Ramzan were now in mourning. Lashkar-e-Jhangvi, a Sunni extremist group, claimed the twin bombings at a crowded market in the Shia-dominated town, linking them to sectarian fighting in Syria.

Dr. Sabir Hussain, an official at a government-run hospital in Parachinar, said they had received 261 victims of the twin blasts, with 62 listed in critical condition.

Another 14 people were killed on Friday in a suicide car bombing near the office of the provincial police chief in the southwestern city of Quetta, police spokesman Shahzada Farhat said. That attack was claimed by a breakaway Taliban faction and the Islamic State group. Gunmen in the port city of Karachi attacked police officers at a roadside restaurant, killing four of them before fleeing, senior police officer Asif Ahmed said.

Maj. Gen. Asif Ghafoor, a military spokesman, linked the attacks to alleged militant sanctuaries in neighboring Afghanistan and promised greater border security. The two countries often accuse each other of turning a blind eye to militants.

Security forces raided a militant hideout in the northwestern city of Peshawar before dawn on Saturday, triggering a shootout in which three Pakistani Taliban were killed and two police officers were wounded, senior police official Sajjad Khan said. He said the militants were making bombs that likely would have been used to target holiday festivities.

Mr. Khan said the identity of the slain militants was not immediately known. But intelligence officials said one of the men has been identified as a wanted militant commander linked to the IS group. They spoke on condition of anonymity because they were not authorised to release the information.

Prime Minister Nawaz Sharif condemned the attacks, which came just days before Eid-al-Fitr, the Muslim holiday that marks the end of the fasting month of Ramzan.

Friday’s car bombing in Quetta could be heard across the city, and shattered the windows of nearby buildings, said police spokesman Shahzada Farhat. TV footage showed several badly damaged cars and a road littered with broken glass.

Quetta is the capital of Baluchistan province, which has long been the scene of a low-level insurgency by Baluch nationalists and separatists, who want a bigger share of the region’s resources or outright independence. Islamic militants have also carried out several attacks in the province.