Darwin homes left without power

Thousands of residents in Darwin were left without power on Wednesday morning after an explosion at an electricity sub-station.

Thousands of properties across Darwin were left without power after an explosion and fire at an electricity substation injured one worker.

Power and Water Corporation spokesman Malcolm Conway said a "routine action" caused a fault on Wednesday, sparking the small explosion and fire.

One worker was taken to the Royal Darwin Hospital for treatment to minor burns.

The incident cut power across four suburbs - Anula, Holtze, Berrimah and Leanyer - leaving more than 4000 properties without electricity.

But Mr Conway said the power load was transferred to alternative supply routes with supplies restored to all customers within four hours.

"Crews responded, making the area safe and isolating the substation," he said in a statement.

The corporation continued to investigate the cause of the incident and was working with WorkSafe NT, Mr Conway said.