A suicide bomber blew himself up and killed four people after striking a truck carrying police officers on their way to protect polio workers.
The Pakistani Taliban claimed responsibility for the attack in the southwestern city of Quetta, Pakistan which injured around 27 people, around 20 of whom are police officers.
Ghulam Azfer Mehser, a senior police officer, said the attack happened as they were heading to the polio workers, part of a nationwide vaccination drive launched Monday.
