Iranian 20-inch crude oil transporting pipeline exploded during a search operation, Shana News Agency reported.
The fire that resulted from the explosion was contained and rescue teams were sent over to help the injured employees.
Bijan Zanganeh, Iranian Oil Minister, urged investigation bodies to figure out the causes of the explosion, S&P Global Platts said.
The explosion led to the death of three employees and the injury of four.
The crude oil pipeline is located in Southern Iran and set to transfer oil from Cheshmeh Khosh to Ahvaz.