Olympic GamesGreece starts a 100-day sprint today to the opening ceremony of the Athens Olympics still without a roof over the main stadium and weighed down by crushing and expensive security demands.

Organisers, frantically rushing to complete building with just over three months to go to the August 13th start, insist that despite years of delays the Greek capital will be ready.

"We will stage an extraordinary, safe and successful Olympics," the deputy culture minister in charge of the Games, Fani Palli-Petralia, said yesterday. "We are working triple shifts everywhere and we will be ready."

Petralia disclosed the government had increased the Games security budget to €1 billion, up by more than 50 per cent from the 650 million announced last October, itself an increase of 25 per cent on the previous estimate. The hike is due to growing concerns over safety at what will be the first summer Games since the September 11th, 2001, attacks on US cities.

On the construction front, organisers got a thumbs-up from the International Olympic Committee yesterday.

"All the reports I receive indicate how fast and how hard Greece is working to complete preparations," IOC president Jacques Rogge said. "As we enter the final stretch together, most of the preparations are already complete."

Games chief Gianna Angelopoulos said: "We believe the Athens Games will be symbolic because this is the country where they were born, where they were revived, and this is the country where the athletes decided to put down their arms during the Games so I think it's a strong message going out."

But a lot still needs to be done before August 13th. Of 39 key Olympic installations, organisers have so far completed construction work on only 18.

Most others are near completion, but much-needed landscaping remains to be done and key transport projects are still under construction.

A new suburban railroad and tramline linking the city with the international airport and the southern coastline are far from ready, although the government has pledged they will be delivered by the end of June.

But the biggest concern remains the steel dome above the main Olympic stadium, which organisers hope will become the Games' architectural trademark.

Two huge steel arches that will carry the 18,000-tonne roof are still not in place and organisers have repeatedly postponed the final assembly date, which is now set for the weekend.

The IOC has warned if the arches are not in position by May 20th, the roof, designed by Spanish architect Santiago Calatrava, must be scrapped.

Petralia said: "We are turning nightime into day and I am convinced the project will be ready and will be magnificent."

Greece is also fighting a public-relations war after growing global security concerns prompted a flood of international media reports questioning the Games plans.

US, British and Australian media have harshly criticised security arrangements, saying venues are currently left unguarded and overall safety plans have been compromised by ongoing construction.

Despite putting together the most expensive security plan in Olympics history and deploying three times as many guards as in Sydney four years ago, organisers have so far failed to ease international concerns.

Greece will mobilise half of its military and security forces during the Games, putting more than 45,000 armed guards on the capital's streets.

Eager to ease international concerns, Greece has said security is the Games' top priority.

Organisers have installed about 2,000 cameras on the streets of Athens to monitor crowds and traffic during the August 13th-29th Games and set up security perimeters - "red zones" - around the 39 Olympic venues. They have also called on NATO to assist with air and sea patrols, and a seven-nation Olympics advisory group comprising countries with extensive security experience has been set up.

The organisers have also played down a row over security arrangements for the Olympic torch which is threatening the opening leg of the flame's record-breaking route around the world.

Sydney, host of the 2000 Olympics, is due to be the starting point on June 4th for the torch's two-month journey.

But the leg is in doubt after state governments in New South Wales and Victoria rejected what they said were plans by Athens organisers to send their own Greek security guards to protect the torch.

Australian Olympic Committee president John Coates said the Sydney and Melbourne legs, for which 277 torchbearers are planned, would not proceed unless a solution was found.

However, Athens organising committee spokesman Serafim Kotrotsos said yesterday: "We have absolutely no involvement in security for the torch relay in the 27 cities around the world."

He said there would be Greek personnel accompanying the torch but local authorities would provide security.