THE Olympic Games will open today in the spirit of peace - but with the grim spectre of terrorism casting its shadow.

The 28th Olympiad will be held amid the biggest security operation the world has ever since the 9/11 New York atrocity and Southampton's Queen Mary 2 will be at its epicentre.

It is a sad irony that the worldwide games, with its tradition of goodwill and harmony, should now be the potential target for extremist fanatics.

Cunard's 151,400 ton QM2 has sailed right into the heart of this hotbed of concern and alarm as international leaders and VIPs join her sumptuous decks and move into the liner's ultra-luxurious suites and penthouses, some costing around £2,000 a night, for the opening of the prestigious sporting event tonight.

As QM2 lies at Piraeus, the port complex just a few miles from Athens, the huge vessel is surrounded by military firepower both on land and at sea protecting the high-profile vessel that dominates the other seven cruise ships being used as floating hotels during the games, in which 28 sports will be represented at 38 different venues.

The cruise ships include one from Germany, three from Greece, a Dutch vessel and two operated by American companies while two smaller 4,260 ton vessels have been chartered exclusively by members of Saudi Arabia's royal family for their personal use throughout the Olympics.

Among the politicians and diplomats expected on QM2, chartered by the Olympic Committee at £1million a day, are Tony and Cherie Blair together with French president Jacques Chirac and former US president George Bush senior. The Blairs could be staying in either the ultra-luxurious Balmoral or Sandingham suites overlooking the stern of the liner.

The ship has been chartered until Monday, August 30, the day after the Olympics finish.

The president of the Athens 2004 organising committee, Gianna Angelopoulos-Daskalaki said the presence of QM2 would not only boost the deluxe capacity of the hospitality programme but would also"add special glamour to the port of Piraeus.''

If these names were not enough to spark the full-scale safety measures now in place, security was ratcheted up another notch only a few days ago when one of the Royal Navy's top commanders revealed intelligence that terrorists were thought to be plotting to blow up ships, with cruise vessels especially in their sights.

Even before QM2 arrived in Greek waters the local authorities closed Piraeus while naval frogmen swept the bottom of the harbour and delicate laser detection equipment was installed.

The worst case scenario would be that al-Qaida sends a suicide mission with a fast speedboat packed with bombs similar to that launched on the warship, USS Cole in 2000 when 17 American servicemen were killed in the Yemen.

In an attempt to counteract any terrorist activity the Greek authorities are reported to have brought in roof-top snipers, thousands of soldiers, including crack special forces, and anti-missile emplacements while the whole deployment is over-flown by helicopters and surveillance aircraft.

Some 70,000 security personnel will work at the Olympic Games including 25,000 from the police, 7,000 from the military, 3,000 coastguards, 1,500 fire-fighters, 3,500 private security contractors and 5,000 trained volunteers. In addition NATO troops are on standby and part of the US Mediterranean based fleet is also patrolling the waters off Greece.

They will be safeguarding 10,500 athletes, 5,500 team officials, many hundreds of thousands of spectators and 21,500 media representatives covering the games over the next 16 days.

A vast network of closed circuit television cameras has been established across Athens that has been linked to the latest hi-tech digital gadgetry that has cost more than £180 million out of a total security budget of almost £1 billion.

Images and audio from the electronic web of more than 1,000 cameras and even a sensor-equipped airship together with four mobile command centres will be subjectto intense scrutiny by the latest computer software.

Intercepted spoken words will be transmitted to speech-recognition systems and then transcribed into text and then searched for any suspect patterns of conversation.

Cunard as a matter of company policy never discuss any matters of security connected with passengers or their vessels.

Greece was the birthplace of the ancient Olympic Games. The first modern Olympics were held in Athens in 1896. This year the event returns to its origins with the Games of the 28th Olympiad.