LONDON — London’s Stansted airport delayed, diverted and canceled some flights after a lightning strike on an aircraft fueling system during storms that unleashed more than 64,000 thunderbolts.

British skies were lit up by the electric storms overnight and there were reports of flooding and homes left without power after torrential rain.

Stansted is London’s third-busiest airport and is a key hub for the discount airline Ryanair, which said that its customers could get a full refund.

“A number of flights have regrettably been cancelled at Stansted Airport this morning due to an earlier airport fueling system failure, caused by a lightning strike,” a spokesman said.

Britain is in the middle of a long holiday weekend, and budget airline Ryanair couldn’t say how many of its flights had been affected at the airport, but was offering full refunds to some.

The fueling system was repaired on Sunday morning, but passengers were warned to check before traveling and passengers stuck on planes complained on Twitter that they were not given proper explanations for the delays.

“Engineers have been on site and have now restored the system. However flights may still be subject to diversion, delay or cancellation,” Stansted said in a statement.

British meteorologists say up to 20,000 lightning strikes hit the UK during a powerful overnight thunderstorm.

Meteorologist Charlie Powell said information suggested there were “somewhere between 15,000 and 20,000 strikes across the UK during the overnight period.” — Agencies