LONDON, June 30: Wimbledon intensified security on Saturday with extra police ringing the tournament grounds and vehicle checks stepped up after the discovery of two car bombs in central London.

Spectators were urged to be extra vigilant and security guards meticulously checked the bags of people coming into the tennis tournament. Sniffer dogs were also sent out to hunt for hidden explosives.

The British capital was on high alert for further attacks after Friday's discovery of explosives in two parked Mercedes cars in London's West End that had echoes of an earlier al Qaeda plot.

The car bombs prompted police at Wimbledon in southwest London to review security with tournament officials.

Superintendent Peter Dobson said he had made adjustments to perimeter security “with some police officers redeployed from inside and some enhanced checking of vehicles entering the car parks.”

But he sought to quell the fears of weekend spectators.

“There is no intelligence that increases the threat to the championships,” he said. “My message is for all persons attending to remain vigilant and to report anything suspicious to police.

Dobson said “This is a timely reminder that the dangers are ever present. The organisers, urging tennis fans to arrive in plenty of time, ordered security officials to be “extra vigilant and diligent in their searching of vehicles and bags. We would ask spectators to mirror that vigilance.”

Police had already tightened and revised security at Wimbledon because the Centre Court could be more open to attack now that its upper levels have been removed for renovations.

With the roof off the world's most famous tennis court in preparation for construction of a retractable cover, the royal box and its VIP guests are now much more exposed.

In fine-tuning security for Wimbledon 2007, police also played out another possible scenario that they needed to counter – an aerial attack.—Reuters