Updated at 6:15 a.m.: One American was among at least 15 killed in a head-on train crash in southern Poland late on Saturday, NBC News reported.

The US Consulate in Krakow told NBC News that the family of the American has been notified, but declined to release and further details on the victim.

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At least 14 others died in crash, described as the country's worst in more than two decades.

"Everything indicates that this is one of the most serious railway catastrophes of recent years in our country," Transport Minister Slawomir Nowak told TVN24 in a telephone interview. "There are people who have died, there are many injured people."

The two trains carrying an estimated 350 passengers were heading in opposite directions on the same track when they crashed at high speed in a rural area near the town of Szczechociny. At least 54 injured people were sent to hospitals.

One of the green-and-cream colored carriages of an intercity train traveling to Warsaw had jack-knifed upwards from the force of the crash. Other cars had derailed and were lying on their sides.

"This certainly is the most tragic train catastrophe in our history in many, many years," said Prime Minister Donald Tusk, who arrived at the site of the crash with several other government officials early on Sunday.

"At the moment we cannot with full responsibility give the final number of fatalities. We should expect at least 14, but we fear this number could rise to 15," he added.

Later the death toll did climb.

Tusk said it was too early to speculate about the cause of the collision, but added that human error could not be excluded.

The fate of the two drivers was not immediately known as the authorities were still identifying the dead bodies.

'I felt the blow'
More than 350 firefighters rushed to the scene, but had to carry their equipment by hand because the trains collided in the middle of a field crossed only by the train tracks.

With the aid of a sniffer dog, rescue workers continued to search for other victims in the mass of mangled steel, where Tusk said they found at least one additional body, most likely dead.

"I felt the blow," an unnamed survivor told public television. "I hit the person before me. The lights went out. Everything flew. We flew over the compartment like bags. We could hear screams. We prayed."

The injured were transported to nearby hospitals. Among the passengers were several Ukrainians along with French and Spanish citizens, but none of them were hospitalized.

One of the trains had been going from Warsaw from to the town of Krakow and the other from the Polish capital to the town of Przemysl.

Reuters and The Associated Press contributed to this report.

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