ROME - Police divers are searching the Tiber in Rome for a 16-month-old boy who witnesses said was thrown into the river by his father.

Carabinieri police began searching after a witness after dawn Saturday reported seeing a man, standing on a bridge crossing the Tiber, toss a baby into the frigid waters about 10 metres below.

Police say they later found the man in another part of Rome and arrested him.

Italian media reports say a relative told investigators that the man had argued with his wife before grabbing the baby and running out of his home.

The Italian news agency ANSA said the man, whose identity hasn't been made public, confirmed to police that he had thrown his son into the river.