A security official deployed to provide security to polio vaccination teams was martyred in Khyber Pakhtunkhwa's (KPK) Tank district on Sunday.
Following the incident, police and security personnel reached the site and launched a search operation.
This is the second attack in two days on polio teams in Tank.
Policeman on polio duty shot dead in KPK's Tank district
On Sunday, a policeman was martyred and an officer of Frontier Constabulary (FC) was injured in a gun attack in the same district.
Sunday's attack was claimed by the Tehreek-e-Taliban Pakistan (TTP).
On Thursday, TTP declared an end to a month-long ceasefire, accusing the government of breaching terms, including a prisoner release agreement and the formation of negotiating committees.
Last week, Prime Minister Imran Khan had directed the district governments to take responsibility to initiate deterrent legal action in cases of harassment or attacks on polio workers.