The incident occurred at the village located 80 km from Bhakkar city in Punjab, police said.
The three terrorists were killed instantly, Superintendent of Police Saifullah Khattak told reporters.
Police launched a search operation in the area after the blast.
A civil defence team was called in from Bhakkar city to defuse other suicide vests found in the possession of the dead terrorists, officials said.
Lahore: Three terrorists were killed when a suicide jacket they were preparing, exploded at a village in Pakistan's Punjab province on Thursday.
First Published: Thursday, September 06, 2012, 18:45