Australian Olympic chief John Coates believes security will be tight in the athletes village at the 2004 Games but is concerned about the rest of Athens.
"You would like to think that things like the Olympic village would be the safest place in the world at the time of the games," he said.
"The problem will be some of the soft targets around the town - nightclubs, bars, those sort of things."
Coates said athletes would be advised not to go into Athens if necessary.
He also revealed that every Australian competitor will be contactable via text messaging on mobile telephones.