On 27 July 1988, Mersad operation[Eternal Light] which took place in a narrow passageway named Mersad in Kermanshah province, western Iran, was a decisive defeat for Mujahedeen-e-Khalq (MKO) terrorist group.
The leadership of MKO was deluded in thinking that members of their terror group will face little or no resistance in Kermanshah province and will quickly reach Tehran in short period, and with the support of Saddam Hussein, the Iraqi dictator, they decided to attack Kermanshah province in western Iran.
Forces of the Islamic Revolution Guard Corps (IRGC) and the Iranian Army surrounded and destroyed the terrorist group in the Mersad operation.