Two trains have collided south of Rome, injuring at least 40 people, four of them seriously.
One train rammed another, which was stopped at the station in Roccasecca, a town about 120km (75 miles) south of Rome, officials said.
The cause of the collision, which left several carriages crumpled and some overturned, remains unknown.
"There are injuries, but we don't know how many at the moment," said Italian railways spokesman Marco Mancini.
"A regional train was making the journey between Rome and Cassino and hit another that was stopped at the station," he told AFP news agency.
Police, Carabinieri (paramilitary police), firefighters and volunteers were helping passengers at the scene.
"There are dozens of people injured and there is blood everywhere," said Valentina Carlino, an eyewitness quoted by AGI news agency.
Transport Minister Pietro Lunardi said he had ordered an investigation.
A spokesman for state railway operator Trenitalia, Luigi Irdi, told the Associated Press news agency the reasons for the collision remained unclear.
Mr Irdi said two people appeared to be missing after the crash.
Italy's last serious train crash was in January, when a passenger train and a freight train collided head-on near Bologna, killing 17 and injuring 60.