'We have identified five main suspects of an explosion in Nikshahr and the police are making efforts to identify them,' Provincial Police Chief Brigadier General Hossein Rahimi told IRNA on Friday.
A policeman was killed while an explosive trap was blasted at the mountainous region of Nikshahr in this southeastern Iranian province on Wednesday.
The explosive trap was planted en route of the police forces who were conducting a mission in that region.
The explosion also made some of the forces injured.
Rahimi said the Police are investigating the issue.