MOSCOW (Sputnik) — According to the BBC, citing a local minister, the blast took place in the city of Quetta in the morning as workers were reporting for duty.
Pakistani militants oppose polio vaccination, considering it to be a Western conspiracy to sterilize children, the media outlet said.
Attacks against health workers are common in Pakistan. In 2013, the Tehreek-i-Taliban Pakistan group attacked a polio vaccination team, killing 11.
15dead. #Barbarians attack #Polio campaign. So want2 send prayers of safety to #Quetta, if only they would be heard! pic.twitter.com/8g9bN6XZ1b
— Adil Najam عادل نجم (@AdilNajam) 13 января 2016
At least 20 people sustained injuries, according to local TV channels. The police are investigating whether the explosion was a suicide bombing.