Police say a bomb has exploded near the Tomb of the Unknown Soldier and Parliament in central Athens. They say nobody was injured in the blast.

An anonymous caller had telephoned a national newspaper about 17 minutes earlier warning that a bomb had been planted, and police had cordoned off the area before Saturday's blast, shutting down a major avenue in the center of the capital.

Police say the explosive device had been placed in a trash bin in the area in front of Parliament, near the Tomb of the Unknown Soldier.

Several extremist left-wing groups operate in Greece, and they often plant bombs targeting businesses, government offices and banks. The bombs are usually planted late at night or preceded by warning calls and rarely cause any casualties.