Luggage was being sorted manually before being loaded on to planes because the computer that operates the terminal's baggage system crashed, Sky News reported.

"We apologize to British Airways and all passengers who have been affected and can assure them that our specialist staff are working hard to resolve the problem and keep disruption to BA's operation to a minimum," an airport spokesman said.

Since Terminal 5 opened last week, about 19,000 lost bags had to be transported to Milan, Italy to be sorted and hundreds of flights have been canceled.