At least 15 people were killed and 25 wounded on Wednesday when a bomb blast targeted a polio eradication center in the city of Quetta, located in southwestern Pakistan.

The bomb reportedly hit a police van that was accompanying health workers in a drive aimed at immunizing young children.

"The police team had arrived to escort teams for the polio campaign," Ahsan Mehboob, the provincial police chief, told Reuters. He added, "It was a suicide blast, we have gathered evidence from the scene."

According to Reuters, two groups claimed responsibility: the Pakistani Taliban and Jundullah, which has ties to the Taliban.