At least six men, including two polio workers, were kidnapped Monday from a rural area in Frontier Region Tank of Pakistan.
A driver accompanying a team of two polio vaccination workers and three security personnel were picked up when the team was on routine duty at Peeng village in Frontier Region Tank.
The kidnapped men included Khandad and Fareed Taleem Ullah, who were working for the polio vaccination programme, Dawn online reported citing its sources.
The incident came a day after a policeman deployed for a vaccination campaign was killed in a bomb attack in Peshawar.
Frontier Region Tank lies on the outer boundaries of Khyber Pakhtunkhwa's Tank district and separates it from the Federally Administered Tribal Areas governed by the tribal laws.
Pakistan is one of only three countries where the polio virus remains endemic.
According to the World Health Organisation, Pakistan recorded 91 cases of polio last year, up from 58 in 2012.
It warned earlier this year that Peshawar was the world's "largest reservoir" of polio.