The attackers fled the scene on a motorcycle after attacking police officers in Mardan district in Khyber Pakhtunkhwa province.
According to police, gunmen riding a motorcycle have killed two police officers assigned to protect polio vaccination workers in northwest Pakistan.
The attack took place on Wednesday in Mardan district in Khyber Pakhtunkhwa province while officers returned to a police station after providing security for the polio team.
Police officers died on the spot while attackers fled. All polio workers were safe. Police said they launched a manhunt to find the perpetrators.
There were no immediate claims of responsibility for the attack, which came two days after Pakistan launched a nationwide action to eradicate the paralyzing disease by the end of the year.
The one-week effort aims to vaccinate tens of millions of children under the age of five with the help of about 260,000 front-line workers.
Pakistani fighters regularly stage attacks on polio teams and the police escorting them, saying the anti-polio action is part of a Western conspiracy.
These attacks escalated after it was revealed that a fake hepatitis vaccination campaign had been used as a ruse by the CIA in the hunt for al-Qaeda leader Osama bin Laden, who was killed by American commandments in 2011 in Pakistan.
In January, a policeman was killed in a similar shooting in the province, while in March, gunmen killed three women participated in a polio vaccination program across the border.
The challenges faced by polio teams have raised fears that any action to inoculate the population against the coronavirus will also have problems.
To date, Pakistan has reported about 936,100 COVID-19 cases and more than 21,000 deaths.
The country and neighboring Afghanistan are the only two in the world where polio is still endemic after Nigeria was declared virus-free last year.
Pakistan, home to 220 million people, now has only one case of polio this year, but the number was high from 147 in 2019 before falling to 84 last year.