A police officer, who sustained severe injuries in a roadside bombing aimed at protecting polio vaccination workers in northwestern Pakistan, passed away in a hospital on Tuesday. The attack, which has been claimed by the Pakistani Taliban, has now resulted in a total of seven deaths.

According to a statement from the police, three officers are still in critical condition following the bombing on Monday in Mamund, a region previously controlled by the Pakistani Taliban in the province of Khyber Pakhtunkhwa which shares a border with Afghanistan.

The Pakistani Taliban quickly admitted to being behind the attack. Yet, on Monday, the Islamic State group made a counterclaim, accusing the Pakistani Taliban of falsely claiming responsibility for the bombing. These two militant groups have a history of competing claims in the region where they both operate.

Polio is still prevalent in only two countries globally, Pakistan and Afghanistan.

The bombing in Mamund on Monday occurred during the government’s routine vaccination efforts. Extremist groups frequently attack polio workers and their police escorts, spreading false accusations that the vaccinations are part of a Western plot to render children infertile.

The second day of the vaccination campaign in Mamund was halted on Tuesday.