The state-railway Freccia Rossa train went off the rails while traveling at nearly 300 kph (180 mph), Civil Protection chief Angelo Borrelli told state radio.

Authorities said the train engineer and another train employee, apparently also an engineer, were killed in the crash, which occurred about 5:30 a.m. (0430 GMT) in the countryside outside the town of Lodi.

"The engine car car derailed, detached completely and kept going,'' Girolamo Fabiano, a railroad police official told state radio. "Then the second car derailed."

The second car was believed to be a business class passenger car. The rest of the cars remained upright.

Given the early hour, the train was uncrowded, with only about 30 people in all aboard, police said.

Fabiano said that work had been done on that stretch of line during the night. He said the cause of the crash, which was under investigation, was unclear.

Borrelli said the high-speed state railways train had departed from Milan at 5:10 a.m. (0410 GMT) and was headed south to Bologna when it derailed. Borrelli said two of the injured were in serious condition, while the other 25 were less seriously injured.

The passenger train run is part of a popular high-speed rail service known as Freccia Rossa, or the Red Arrow service. Its southern destination was supposed to be Salerno, a port city south of Naples.

Rail traffic was diverted to local tracks, with delays of about an hour reported.