The incident occurred on Safaid Sang Road on the outskirts
of Peshawar in Khyber-Pakhtunkhwa province where the trio were likely planning an attack, police said.
"The suicide bombers were killed when suicide vest of one of them went-off," they said.
Police defused a suicide jacket tied on the body of a second would-be bomber and recovered nine grenades and one AK-47 from the site of the explosion.
The identity of the victims could not be immediately ascertained. Their bodies were taken to nearby hospital for postmortem.
The trio could also be the supplier of explosive material for some major terror attack in the city, police said.