Heathrow airport in London says some flights have been resumed following power outage caused by fire

London's Heathrow airport announced Friday that some flights have been resumed after a power outage that was a result of a massive fire the day prior.

"Our teams have worked tirelessly since the incident to ensure a speedy recovery," the airport wrote on the social media platform, X. "We’re now safely able to restart flights, prioritising repatriation and relocation of aircraft."

The airport informed travelers not to go to the airport unless advised to by their airline. They added that they hoped to be back in full operation by Saturday.

Thousands of travelers have been impacted by the power outage.

The fire started in a transformer in an electrical substation in the town of Hayes, in west London. At least 10 fire engines and about 70 firefighters have responded to the blaze, the London Fire Brigade said.

The cause of the fire has yet to be identified.

Hundreds of flights have been canceled or rerouted due to the incident and multiple people had to be evacuated from the airport.

The Metropolitan Police in London said it had counterterrorism specialists leading the investigation, according to The New York Times.