A loud bang heard across west Belfast on Friday night was not caused by an explosion, NIE have said.
Social media was ablaze with reports of lights flashing in the sky and power outages. Many theories suggested there had been an explosion.
The incident happened at the power substation on the Suffolk Road but there were reports of it heard further afield.
There were no reports of any injuries as a result of the incident.
The incident resulted in brief power outages in many areas across Northern Ireland.
NIE's Sarah McClintock said a fault had caused a dip in power.
"Equipment failure could cause a bang and a flash which we believe is what people saw last night," she said.
"There was nothing sinister involved. It was a piece of equipment that failed in one of our sub stations and that would have caused the flash and could also have caused the dip in power that we have seen."
Sinn Fein MP Paul Maskey said online that he thought it was caused by a lightning strike.
Residents in the area described their rooms filling with flashing lights of many colours and their power cutting out.
One eyewitness said their feet were “stuck to the ground” due to the power of the bang.