Authorities are questioning two men suspected of a machete attack on a railway ticket inspector whose arm was nearly detached.

Police said a group of at least four men attacked the inspector late Thursday night on a regional train north of Milan. The dynamics of the attack were not immediately clear.

The attackers also attacked another railway worker who intervened, causing a head injury.

Police said that the musculature of the inspector's arm was reattached during surgery.

Police identified two men with bloody hands as suspects and detained them for questioning. They were identified as South Americans.

Italian State Railway appealed for a greater police presence on trains nationwide.