Bomb shatters windows in Athens

A bomb exploded outside the offices of a Greek business federation in central Athens early on Tuesday, smashing windows but causing no injuries, police officials said.

The blast, which police believe was carried out by domestic guerrilla groups, is the first such incident since Prime Minister Alexis Tsipras came to power in January.

Attacks against banks, politicians and businesspeople are not uncommon in Greece, which has a long history of political violence and has been mired in its worst economic crisis in decades.