A bombing near a girls' school in western Pakistan on Friday resulted in the tragic deaths of seven people, including five children, during an attack aimed at police protecting polio vaccinators, officials reported.

"The police van that was targeted was transporting personnel assigned to safeguard polio workers," said Rahmat Ullah, a senior police officer, in a statement to Agence France-Presse (AFP).

He noted that "a girls' school is located near the site of the attack" in Mastung, Balochistan province.

Pakistan and neighboring Afghanistan are the only countries where polio remains endemic, and vaccination teams are frequently targeted by militants waging a campaign against security forces.

"Seven people – one police officer, five children, and one shopkeeper – were killed in the attack at the city's main market," senior officer Abdul Fatah told AFP.

Interior Minister Mohsin Naqvi earlier put the death toll at three children and one police officer.

"Targeting children is an act of brutality," he said in a statement.

No group immediately claimed responsibility for the blast.

Earlier this week, two police officers guarding polio vaccinators going door-to-door in northwestern Pakistan were shot dead in an attack blamed on militants.

This attack came a day after Pakistan launched a week-long drive aiming to immunize more than 45 million children over the age of five.

Pakistan has seen a surge in polio cases this year, recording at least 41 so far in 2024, compared with six in 2023.

The country has also been battling a resurgence of militant violence in its western regions since 2021 when the Taliban returned to power in Afghanistan.

Islamabad accuses Kabul's rulers of failing to root out militants staging attacks on Pakistan from across the border.

The most active group in Balochistan is the Baloch Liberation Army, a separatist group that regularly targets Islamabad's security forces and citizens from other parts of Pakistan.