British Airways cancels all Saturday flights from London's two biggest airports

The British Airways has canceled all Saturday flights from London's two biggest airports after "a major IT system failure" caused severe disruption to flight operations worldwide.

The airline said, "There's no evidence it's a cyber attack. We are working hard to get our customers who were due to fly today onto the next available flights over the course of the rest of the weekend. Those unable to fly will be offered a full refund."

The system outage -- on Britain's spring break holiday weekend -- has "affected our call centres and our website but we will update customers as soon as we are able to," the airline added, the CNN reported.

The British Airways has not outlined how many flights were canceled, nor how many people were affected.

The airline said it was "extremely sorry" for passengers' inconvenience and was working to resolve the problem as soon as possible.

The airline officials gave no indication of what might have caused the problem or when it would be fixed.