London ? Blackouts caused by sweltering temperatures struck more than 3,000 businesses in London’s major shopping district and part of its transit network on Thursday, officials said.

High energy demand led to outages starting in the city’s central Soho district, said James Barber, a spokesman for energy company EDF in southeast England.

Barber said the outages were due to a “highly unusual sequence of faults” at substations and in underground cables.

Temperatures on Thursday reached 86 degrees in central London, the Meteorological Office weather center said.

Part of the Oxford Circus subway station, which serves more than 300 nearby stores, was closed for about an hour and a half, causing severe disruption, said James Simpson, a spokesman for the London Underground. He said an estimated 570,000 passengers ride through the station on weekdays.

Barber said sporadic power outages likely would continue into today in the area between Oxford Circus and Piccadilly Circus in central London.