At least one person was killed and some 110 injured on Tuesday morning when two trains on Rome's underground system collided, according to local reports.

The accident took place shortly after 09:45 a.m. local time (0845GMT) at the Piazza Vittorio, an underground station near Rome's main train terminal.

Firemen said a stationary train at the stop was hit from behind by a speeding train on the same line.

The victim was a 30-year-old Italian woman. Initially, the driver of the moving train was also believed to have died but emergency services later denied it.

About 60 of the injured were in a serious condition and at least four were said to be in critical condition, the reports said.

Most of the injured were bruised and shocked.

Badly hurt passengers were ferried to hospital in ambulances and buses immediately after they emerged from the station exits.

According to the reports, a failure on the Metro network's central signaling system was to blame for the accident.

The moving train was believed to have been given the green light to proceed from the station.

"At that point, the crash was inevitable and the impact was very strong. The first carriage of the oncoming train ploughed right into the last carriage of the stationary train," Metro sources said.

Underground rail officials said both trains involved in the crash were brand new, high-tech models only recently introduced to the network.

The Spanish-made trains are supposed to gradually replace the old trains running on the Metro system, the reports said.

Rome Mayor Walter Veltroni, who was at the scene, said that "I've asked Metro managers to explain how a thing like this could have happened. The trains were both new and working well."

The scene at Piazza Vittorio was chaotic with rescue workers taking an hour to help some of the injured out of the trains' wreckage.

Witnesses told reporters they had initially feared it was a terrorist attack.

A journalist with Italian state broadcaster RAI who was on board one of the trains said "the impact was incredibly powerful despite the fact that the oncoming train had slowed down to enter the station."

The accident caused widespread disruption in the capital with suspension of underground rail services and extensive traffic jams.

Italian President Giorgio Napolitano expressed his condolences for the victims of the crash.

Prime Minister Romano Prodi was kept informed of developments by Veltroni and Transport Minister Alessandro Bianchi.

The government would report to parliament on the incident on Tuesday afternoon.

Editor: Yan