India, March 21 -- London's Heathrow Airport has been closed due to power outage caused by a major fire at a nearby electrical substation.

The complete shutdown of Heathrow, one of the world's busiest airports, led to massive disruption in air travel across the world, reports say.

More than 1,300 flights could be canceled From the airport in west London Friday, and it is estimated to affect the travel of around 145,000 passengers.

A number of flights were forced to divert to airports around the world, as airlines came to know about the closure while the passenger planes were mid air, according to flight tracking website Flightradar24.

At least 120 flights were diverted half way through the journey to alternate airports in Europe, it add...