Two Pakistani policemen were killed while guarding teams collecting census data in separate attacks claimed by the local Taliban, police said Tuesday.
Pakistan started a month-long digital census at the beginning of March with security officials deployed alongside more than 120,000 enumerators.
Police are increasingly on the frontline of Pakistan's battle with the Tehreek-e-Taliban (TTP) and are frequently targeted by militants who accuse them of extra-judicial killings.
On Monday, two teams were attacked in Khyber Pakhtunkhwa province, in separate districts close to the border with Afghanistan.
"Gunmen attacked the police party responsible for supervising the security of the census team from two directions," said Farooq Khan, a police official in Tank district, adding that one officer was killed and four were wounded.
Later in the evening, the Pakistani military reported that one militant was killed in an "intense exchange of fire".
In the other attack, men on a motorbike opened fire on police, killing one and wounding three.
"The security measures were further intensified and the census process was resumed," Lakki Marwat district administration official Tariq Ullah told AFP.
The attacks follow a similar assault last week in the same region which left an officer dead.
The TTP, which is separate from the Afghan Taliban but has a similar Islamist ideology, claimed all three attacks.
"Our primary target is the police, regardless of whether they are escorting politicians, polio teams, or census teams," a TTP commander told AFP.
Pakistan is facing overlapping political, economic and environmental crises, as well as a worsening security situation, since the Afghan Taliban took control of Kabul in August 2021.
In January, more than 80 officers were killed when a suicide bomber detonated an explosive vest at a mosque inside a police compound in the northwestern city of Peshawar.
The census is gathering demographic data ahead of parliamentary elections due by October.
Political parties and ethnic groups regularly criticise census statistics for undercounting, data manipulation and other irregularities.