Greece will provide armed guards for some of this year's Olympic athletes who could be considered potential targets for terrorists.
Greece's Ministry of Public Order says guards will be on all buses used to transport athletes during the Athens games. It says the guards will be armed when dealing with athletes of "higher risk" countries.
The United States and Australia are among countries that have requested extra security for their athletes and are part of a seven-nation advisory group helping Greece with security plans.
Greece plans to have more than 50,000 security personnel on duty foir the Summer Olympics, and has budgeted more than $750 million for security.
Along with magnetic gates, X-ray machines, hand-held metal detectors and sniffer dogs, there will also be strict checks on credentials using a new identification system that took four years to develop.