Greek police say a bomb exploded at the Swiss Embassy in Athens, and suspicious packages were detonated outside parliament, the Bulgarian Embassy and a courier company.

No injuries or damage were reported from Tuesday's four small explosions.

Police say far-left domestic groups are suspected.

On Monday, four mail bombs failed to reach their targets — French President Nicolas Sarkozy, along with the embassies of Mexico, the Netherlands and Belgium. Two Greek men were arrested on suspicion of plotting the attacks.

The bombs were found after one of the devices exploded at a delivery service in central Athens, lightly wounding a worker at the delivery company.