In the US colonial territory of Puerto Rico, hundreds of people are forced to live in power outage after a fire in electrical powerplant.

"The fire caused major blackouts across the entire island. The situation is under assessment and work is being done to restore the system," LUMA Energy tweeted, stating that restoration efforts will continue overnight, CNN reported.

About 400,000 customers in Puerto Rico were without power as of late Thursday, LUMA Energy said, which is more than 1 in 10 residents on the island.

The fire broke out shortly after the firm reported a cyber-attack, which has not yet been linked to the fire.

The Caribbean island, in the control of the US, has struggled with rolling blackouts ever since Hurricane Maria largely destroyed its electrical grid in 2017.