Airlines face days of disruption with hundreds of thousands of scheduled passengers already unable to fly in and out of Europe's busiest airport, after what ministers said was an "unusual and unprecedented incident".
London fire brigade was called shortly after 11pm on Thursday to a fire at an electrical substation in Hayes, west London, with power also cut to thousands of homes.
More than 70 firefighters tackled the blaze, which the brigade said at 8am was under control, with more than 20,000 litres of oil having caught fire in a transformer. Officers said that despite the acrid smell, there was no air quality danger to the public.
The cause of the fire is unknown, although security sources indicated there was no immediate indication of foul play.
A spokesperson for the Met Police said: "We are working with the London Fire Brigade to establish the cause of the fire which remains under investigation. While there is currently no indication of foul play we retain an open mind at this time.
"Given the location of the substation and the impact this incident has had on critical national infrastructure, the Met's Counter Terrorism Command is now leading enquiries.
"This is due to the specialist resources and capabilities within that command that can assist in progressing this investigation at pace to minimise disruption and identify the cause." The detectives have the security clearance to access sensitive material as investigators try to establish the fire's cause.
Heathrow is regarded a potential target for terrorism or sabotage, the incidence of which, backed by state actors, has been rising in recent years.
National Grid said substation fires were "extraordinarily rare" and it was not able to "rule anything in or out"....<<<Read More>>>...
