Police take no chances locking down fortress Excel

Armed officers carrying sub-machine-guns set up roadblocks at key points around the east London site and sniffer dogs searching for explosives swarmed over the venue after police frogmen secured the docks.

Hundreds of flashing blue lights lit up the morning gloom as teams of officers scouted around looking for anything suspicious. Delegations from across the world were greeted by security measures that gave the centre the feeling of a military base.

The official convoys, including presidents, prime ministers and finance ministers and their teams of officials, were swept through the police checkpoints positioned every 50 yards to the main entrance of the centre.

But other delegates were stopped at the perimeter of the secure zone and either had their cars searched or were made to go on by foot.

Police teams were stationed in every hotel on the site and airport-style bag scanners, knife arches and hand-held metal detectors were deployed at entrances to the centre, where G20 leaders are in talks to try to secure an agreement on how to drag the world economy out of its downturn.

Newham University Hospital set up a medical centre at Excel to cope with any emergencies.

Journalists trying to get the summit venue faced two shuttle bus journeys and several checkpoints before they finally arrived at the media centre.

Hordes of security staff were on hand to check the identification of everyone moving around the venue. Some catering staff arrived at 2am to ensure they got through the security checks on time after their employers laid on taxis.

Police were determined to prevent the protesters who brought the City to a standstill yesterday from getting within striking distance of Barack Obama and the other G20 leaders.

But with Royal Victoria, Prince Regent and Custom House DLR stations closed and police blocking access by road, the demonstrators faced a struggle to get close to the summit. Transport for London said the stations were shut for the day on the "advice of police".

Thousands of police were on duty yesterday in London's financial district, and protests are planned around the Excel centre today with groups planning to meet in nearby Canning Town.

All police leave has been cancelled in the £7.2million operation involving six forces. Scotland Yard said about 4,700 officers would be deployed across London today and this evening. "We believe our tactics worked well yesterday but we are prepared for further demonstrations today," said a spokeswoman.