Authorities in Pakistan reported Monday that gunmen targeted vaccination teams in northwestern districts during a nationwide campaign against the paralytic poliovirus, resulting in the deaths of at least one health worker and two police officers.

The violence in the militancy-hit Khyber Pakhtunkhwa province, which borders Afghanistan, also injured several polio workers and police force members escorting them. There were no immediate claims of responsibility for the attacks.

Pakistan has reported a significant surge in poliovirus infections in 2024, confirming 63 cases so far, compared to only six cases in 2023.

On Monday, the country launched a weeklong house-to-house vaccination campaign, culminating the year’s anti-polio efforts. Officials said the campaign aims to inoculate more than 44 million children under five to protect them against polio.