An explosion in Pakistan's southwestern province of Balochistan on Friday killed at least seven people, including five schoolgirls, and injured 23, a police official said.
“The target was a police van going to pick up a polio vaccination team,” local police chief Rehmat Ullah told Reuters.
A police officer also died.
The explosion was caused by an improvised device attached to a motorcycle parked near a girls' school in the town of Mastung.
No group has claimed responsibility for the attack.
Prime Minister Shehbaz Sharif condemned the attack in a statement.
Pakistan is facing a surge in attacks in the country's northwest and a growing separatist insurgency in the south. On Tuesday, a police officer was killed in an attack on an office managing polio vaccination campaigns.
Pakistan launched its third national polio vaccination campaign on Monday as the number of cases of the viral disease increased significantly. There are currently 41 active cases in Pakistan.
Pakistan and Afghanistan remain the only countries where polio is endemic. Islamist fighters have previously targeted medical teams, spreading false information that vaccinations are part of a Western sterilization program.
(Reporting Saleem Ahmed in Quetta, Pakistan, writing by Ariba Shahid in Karachi; French version Kate Entringer)
