The Big Apple is turning into Big Brother, civil liberties groups have warned in response to a new plan from New York city's police chiefs to photograph every vehicle entering Manhattan and hold the details on a massive database.

New York's police commissioner, Raymond Kelly, has proposed a major extension of security measures around the city designed to prevent a third attack on the World Trade Centre as the rebuilding of Ground Zero gathers pace.

As well as placing cameras at all tunnels and bridges into Manhattan, the 36-page plan, called Operation Sentinel, calls for a security ring to be erected at Ground Zero and for a 50-mile buffer zone around the city within which mobile units would search for nuclear or "dirty" bombs.

The proposals are partly based on the so-called ring of steel erected around the City of London in the wake of IRA bombings in the 1990s. Though the 3,000 cameras that could be mounted as a result of the plans of the New York police pale in comparison with the multitude of cameras in operation on the UK's roads and in public places, the proposals have provoked outrage in the United States, where the concept of video surveillance is relatively unfamiliar.

Civil liberties: Outrage at New York police plan to track vehicles