A loud bang heard across west Belfast and flashing lights seen in the sky was not caused by an explosion, NIE have said.
Social media was ablaze with reports of lights flashing in the sky and power outages on Friday night.
Many theories suggested there had been an explosion.
The incident happened at the power station 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 Northern Ireland Fire Service attended along with Northern Ireland Electricity but they have yet been unable to confirm what had exactly happened.
The incident resulted in brief power outages in many across Northern Ireland.
The NIE insisted that there was no indication of anything sinister.
In a statement NIE said: "NIE Networks confirmed that due to an equipment fault, several thousands of homes and businesses would have seen a dip in power for a number of seconds on Friday night.
"Network protection systems operated correctly to ensure that power supplies were not lost."
Engineers from NIE Networks and SONI, the System Operator Northern Ireland, are investigating the cause.
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.
He told the Belfast Telegraph: “There were lights flashing blue, red and everything.
“I came out of my house and there was a thick black smoke and a horrible smell came with it.”