Three bombs exploded outside a police station in a series of timed blasts Wednesday, causing serious damage but no injuries, authorities said.
The pre-dawn explosions, which occurred over a span of about a half hour, came before events to mark 100 days left until the Aug. 13-29 Olympics. An anonymous caller to an Athens newspaper warned of the attacks several minutes in advance, but gave no motive or claim of responsibility.
Bomb experts conducted a controlled explosion at the site, but it was apparently a suspicious package and not a fourth bomb.
Police believe the bombs at the southern residential district of Kalithea were intended to claim victims despite the tip to the newspaper. Parts of the building were extensively damaged. Authorities evacuated the station and cordoned off the area.
In September, similar timed blasts damaged a judicial complex in Athens and injured one police officer. The twin bombings, spaced 20 minutes apart, were claimed by a group calling itself Revolutionary Struggle and believed to be a protest against crackdowns that toppled the deadly November 17 terrorist cell.
Greek authorities — under intense pressure safeguard the Olympics — claimed they crippled domestic terrorism following the convictions in December of 19 members of the group, blamed for 23 killings and dozens of other attacks since 1975. The victims include four U.S. officials, two Turkish diplomats and a British defense envoy.
But smaller groups have continued to carry out bombings and arson attacks in Athens and other cities, but most are against cars and commercial targets and rarely cause injuries.
An International Olympic Committee inspection team is scheduled to arrive in Athens on Monday for a final review of preparations.