Updated

Private jets and ultralight aircraft will have already tight restrictions on flying over London expanded further during the Olympics, a senior air traffic controller said Sunday.

The zone surrounding London from which private planes, hot air balloons and ultralights are banned will increase by up to 30 miles (48 kilometers) in all directions, said Paul Haskins, who runs the London terminal controls of the National Air Traffic Services. The restrictions are for security and to minimize the chances of a crash between a private plane and a jumbo jet.

He said military chiefs would have to assess whether an unauthorized pilot who strayed into the airspace had done so by accident or posed a security threat.

"During the Olympics if you start infringing London's airspace and you're heading towards one of the key stadiums, the Ministry of Defense is likely to see you as a threat," Haskins said

The monthlong restrictions come into force on July 16.

National Air Traffic Services, which is responsible for airspace used by commercial airliners, will be the first to know if a plane enters restricted skies, triggering automatic responses which could lead to the Royal Air Force launching its Quick Reaction Alert Typhoons to intercept suspect aircraft.

Some 4,000 extra flights are expected to come into the U.K. for the games. As well as the extra planes bringing fans, Olympics officials, athletes and media to the capital, three aircraft will hover over Games' venues providing television footage of events like the marathon and road cycling, with another three nearby.