QUETTA: Two suspected militants blew themselves up during exchange of fire with security forces in Balochistan's Zhob district late on Sunday.

Levies sources told Dawn the incident took place when security forces were carrying out a search operation for the recovery of kidnapped polio workers and levies personnel in Margha Kibzai area of Zhob district.

Three polio workers and two levies men went missing in Balochistan's Zhob district on Friday, sparking fears that they were kidnapped by militants. Levies sources told Dawn that five persons went missing in Murgha Kibzai area of Zhob.

"The dead bodies [of suicide bombers] are under the custody of forces," said the levies official. Meanwhile, the polio workers and two levies personnel are still under the custody of militants.

More troops were called into the area to ensure unhurt recovery of kidnapped polio workers and two levies personnel. "The situation is tense in the area," said levies said.

The polio workers and levies personnel were coming back to Zhob when their contact was lost. Kidnappers had also left polio team's ambulance in the area.

"The families lost contact with the polio workers since this morning," a levies official who requested anonymity told Dawn.

Acts of kidnappings have increased in the area after repeated operations by security forces. This incident has come a week after abduction of six PTCL workers in the same area.