A bomb blast at a polio center in restive southwest Pakistan killed 14 and injured 25 on Wednesday, according to police.
Twelve of those killed in the city of Quetta were police officers, local police chief Rab Nawaz Khan said. Nine of the 25 injured were listed in critical condition, he added.
The bomb exploded outside the center shortly before vaccination teams were scheduled to travel to neighborhoods as part of a three-day immunization campaign, another local police chief Syed Imtiaz Shah told Reuters.
"Today was third day of the campaign and the police were supposed to provide security to the polio teams," Khan told NBC News. Officials were still figuring out whether the blast had been caused by a roadside bomb or a suicide bomber.
