American, British and Israeli athletes are to be given 24-hour armed guards to protect them against terrorist attacks during this summer's Athens Olympics.
The Greek government is staging an unprecedented security operation at an estimated cost of 1bn euros ($1.2bn).
Competitors from the three countries are considered to be among the most likely potential terrorism targets.
A spokesman for the Greek ministry of public order said the cover would extend beyond the athletes' village.
"We are talking about armed guards for every official and non-official activity," he said, including sightseeing and shopping.
The guards will travel on athletes' buses, which will also be protected by armoured vehicles and police helicopters.
Athletes from other countries which have sent troops to Iraq may also receive similar protection.
The Sunday Telegraph reported that the plans have been approved by the seven-nation advisory group on security, which is chaired by Scotland Yard's head of special operations.
Greek officials denied that the measure was in response to British and US requests to use their own armed guards.
The British Olympic Association said last week that it was happy with security arrangements for the Games.