PESHAWAR: At least five cops were killed and 22 people injured on Monday after a bomb went off near a police van in Pakistan's Khyber Pakhtunkhwa province, officials said.

According to the police, the van was targeted with an improvised explosive device in Bajaur district, reports Xinhua news agency.

The personnel were on their way to provide security to polio vaccination teams in the district when they were targeted, said the police.

The polio vaccination drive was suspended as a result.

Following the incident, a heavy contingent of police, along with rescue teams, reached the area and shifted the injured to a nearby hospital, where several othe wounder were said to be in critical condition.

Security forces cordoned off the area and have launched a search operation.

No group or individual has claimed responsibility for the blast.