Security clampdown on low flying

New security restrictions have been imposed on low-flying aircraft in London.

Pilots taking private planes over the capital will need special permission to go below 1,400 feet in three zones.

They are centred on the potential terrorist targets of Buckingham Palace, the City and Canary Wharf.

The measures come into force on 28 October and will allow Scotland Yard to know who is in the air at all times.

But the Government and police emphasised they have not been introduced as a result of a specific threat.

The restrictions have been outlined in a circular distributed by National Air Traffic Services on behalf of the Civil Aviation Authority.

It said Transport Secretary Alistair Darling "deems it necessary in the public interest" to restrict flying on behalf of the Metropolitan Police for reasons of national security.

Aircraft and helicopters will have to get written permission 28 days in advance to fly below 1,400 feet in the restricted zones.

Flights to and from Heathrow and London City airports are exempt, as are police and other authorised aircraft, such as air ambulances.

The Department for Transport said the measures were to ensure the police know who is flying over London.

A Met spokesman said: "The procedures are not in response to a specific threat but are to ensure enhanced air traffic management over London."