Gunmen have shot dead two police officers protecting polio vaccination teams in northwestern Pakistan, a day after four officers protecting polio workers were kidnapped.

The attackers, travelling on a motorcycle, opened fire on a police car in Khyber Pakhtunkhwa province on Tuesday. A third officer was injured in the attack, which occurred as the officers were travelling to a nearby village to protect polio vaccination teams.

“Two police personnel were martyred and another was injured in the attack. However, no polio vaccination staff were present in the police vehicle,” police official Ali Rehman Khan told the AFP news agency.

No one has claimed responsibility for the shooting, but similar attacks have regularly been carried out by the Pakistan Taliban, known by the acronym TTP, and other armed groups. These groups falsely believe that polio vaccination teams are part of a Western conspiracy to sterilise children.