London's Heathrow Airport has resumed operation after an 18-hour shutdown due to power loss caused by a nearby substation fire that triggered massive disruption in the city.

The substation fire even left a large number of households in London without power.

About 200,000 passengers were affected as flights were grounded throughout Friday, with inbound planes being diverted to other airports in Europe after flames ripped through the North Hyde plant in Hayes, west London, on Thursday evening, reported BBC.

Full Operation From Saturday

Meanwhile, Heathrow Airport authorities said they expect the facility to operate fully from Saturday.

Authorities asked travellers to consult airlines before travelling to the airport.

The Airport posted on X: "Our teams have worked tirelessly since the incident to ensure a speedy recovery. We’re now safely able to restart flights, prioritising repatriation and relocation of aircraft. Please do not travel to the airport unless your airline has advised you to do so."

"We hope to run a full operation tomorrow and will provide further information shortly. Our priority remains the safety of our passengers and those working at the airport. We apologise for the inconvenience caused by this incident," the airport said.

Several airlines, including British Airways, have said they are resuming operations at the airport.

Fire Under Control

The substation fire which forced the Heathrow operation to stop has been brought under control.

Ten fire engines and about 70 firefighters were rushed to the spot to control the fire.

London Fire Brigade Deputy Commissioner Jonathan Smith said: "The fire involved a transformer comprising 25,000 litres of its cooling oil fully alight. This created a major hazard owing to the still live high voltage equipment and the nature of an oil fuelled fire."

The fire left 65,000 homes in the area without power.

No Foul Play

The Metropolitan Police said the fire incident had no indication of a 'foul play'.

Commander Simon Messinger who is leading the Met Police response to the incident, said in a statement: "Due to the location of the substation and the impact this incident has had on critical national infrastructure, the Met’s Counter Terrorism Command are leading our enquiries into this matter."

“Various specialist investigators continue to examine the scene and it is expected to take some time before full assessments can be completed," the Commander said.

“Officers will continue to work alongside colleagues on the investigation, but as we have stated above, at this stage, there remains no indication of any foul play," Messinger said.