The Greek security forces and emergency services have just completed one of the biggest anti-terrorist exercises ever held in Europe.
The emergency services had to be ready for anything
The exercise, watched by more than 100 observers from around the world was in preparation for the Olympic Games being held in Athens in August.
There are concerns the Games could be targeted by terrorist groups.
The exercise, codenamed "Blue Odyssey", was designed by experts from the British Home Office.
The aim was to test the ability of around 2,000 members of the Greek police, military, coast guard, fire brigade and medical services to react to an attack involving a weapon of mass destruction.
They were told there had been an explosion at a train station near Athens in which nerve gas had been released.
At the same time they had to deal with the hijacking of a group of British and American tourists on board a cruise ship.
More exercises are planned to fine-tune safety plans
No journalists were allowed to watch the exercise, but afterwards, security officials said it had been a success.
The Athens Olympics, which begin in six months' time, will be the first summer games to be held since the 11 September attacks on the United States and the subsequent war on terrorism.
The Greek authorities are leaving nothing to chance and are preparing the biggest security operation in the history of the Olympics.
More than 50,000 members of the security forces and emergency services will be directly involved in protecting the athletes, officials and visitors.
Special equipment will be placed in the capital to detect a chemical, biological or nuclear attack. Nato surveillance aircraft will help patrol the skies.
The total cost for Greece could be more than $1bn.
The defence minister told the BBC they were now ready to face any threat.