The blasts injured a policeman and badly damaged a police station.
Three bombs have exploded outside a police station in the Greek capital Athens. The police say no one was killed or injured, but there was a lot of damage to the building. The attack comes exactly 100 days before the Olympics begin in Athens. This report from Richard Galpin:
All three bombs exploded within half an hour of each other outside a police station south of the city centre.
A national newspaper received an anonymous phone call warning about the attack just minutes before the first device exploded in the early hours of the morning.
A fourth device was found by the bomb squad and destroyed in a controlled explosion. The whole area has been cordoned off and the anti-terrorism unit of the police has begun an investigation.
So far, the police have not said what kind of bombs were used in the attack and no one has admitted responsibility. But suspicion is bound to fall on radical left-wing organisations which have carried out similar attacks in the past.
Last September, two bombs exploded in the precinct of the main law courts in Athens, also early in the morning. The Greek authorities have launched a crackdown on left-wing extremists in recent years because of concerns about security during the Olympics.
The leaders of one organisation responsible for a series of murders and bombings in recent decades were jailed last December and are serving long prison sentences. Members of another smaller group are currently on trial.
Richard Galpin, BBC, Athens
an anonymous phone call
una llamada telefónica anónima
a controlled explosion
una explosión controlada
suspicion is bound to fall on
sin dudas, las sospechas recaerán sobre
radical left-wing organisations
organizaciones radicales de izquierda
a crackdown on
una ofensiva contra