Fans told 'set out early'

In the heart of the city, the stadium is expected to be filled to its 72,500 capacity on Saturday to see Manchester United take on Millwall.

The heightened security alert follows fears last month that Old Trafford could be the target of terrorist attacks.

Although there has been no warning and no specific threat against the FA Cup Final in Cardiff the authorities are taking no chances.

Sniffer dogs

The general manager of the Millennium Stadium, Paul Sergeant is urging fans to turn up well before the 1500BST kick-off and not to carry bags.

"We work very carefully with South Wales Police - they are very experienced operators - and with that combination we're in a position where we can act with confidence," said Mr Sergeant.

Teams of sniffer dogs will check and recheck locations and road blocks on all of the main routes into the city have been in place since Wednesday.

Armed police are carrying out random checks and they are concentrating on vehicles carrying fuel or chemicals.

Stephen Cahill, assistant chief constable of South Wales Police, said there would be road blocks on all of the main routes into the city from Wednesday.

Certain types of vehicles are being targeted by police

"What we're looking for in these checks are vehicles that fit a certain profile," he said.

"That would be vehicles carrying petroleum, chemicals - large-sided vehicles that could easily hide things - armed officers will be in support of this operation," he added.

However the chairman of the Cardiff Chamber of Commerce, Frank Maloney, believes people are in danger of exaggerating the risk of terrorism.

"The only twinge of anxiety I have - and that is as a retailer - in the city centre we lose a reasonable amount of business on the days of big matches.

"This is because of the negative reflection given by the media. The police have proved themselves time and time again - the city will be safer than an average Saturday night," Mr Maloney added.

Deterrent

Charles Shoebridge, a security analyst and former anti-terrorist intelligence officer with the Metropolitan Police, said that although sporting venues are amongst the top tier of targets, the security measures at the Millennium Stadium should make it a safe place to be.

"As far as is known, there isn't anything, from anywhere in the world, to suggest than al-Qaeda is targeting specific sporting events," added Mr Shoebridge.

"In conjunction with more covert activities, high visibility policing serves two important functions.

"It reassures the public, and it acts as a deterrent - not by making a potential attacker worry about being prosecuted, but that his attack is more likely to succeed if attempted elsewhere," he added.

This is the busiest period of the year for the Millennium Stadium with more than 300,000 fans expected to attend five major events in the space of 17 days.

The Nationwide League Play-Off Finals held at the stadium on 29 - 31 May, are also expected to be full or near capacity events.