Chilean prosecutors say a man has died when the bomb he was handling exploded in downtown Santiago.

Prosecutor Claudio Orellana says the unknown young man "had been manipulating a homemade explosive artefact, and in those circumstance, it blew up on him."

The man was taken to an emergency clinic, where he died.

Thursday's explosion follows scores of other small-scale blasts around Chile's capital that authorities have blamed on anarchist cells. The only other fatality also is believed to be a man planting a bomb.

Three alleged anarchists are in custody on suspicion of planting at least four bombs, including one that injured 14 people this month.