Two trains running on the same track collided head-on in southern Poland late Saturday, March 3, leaving 15 people dead and 56 injured - the country's worst train disaster in more than 20 years, AP reports.

Several of the passengers were foreigners, including people from Ukraine, Spain and France, but none of them appeared to be among the dead or badly injured, Prime Minister Donald Tusk said.

Many of the injured are in a serious condition, with some in artificially induced comas.

The accident in the southern town of Szczekociny comes less than three months before millions of football fans will start crisscrossing the country - many by train - to watch matches at the Euro 2012 football championships, which is being co-hosted by Ukraine.

Prosecutors have opened an investigation into how one of the trains ended up on the wrong track, but Tusk said it was too soon to draw any conclusions.

One train was traveling from the eastern city of Przemysl to Warsaw, while the other - on the wrong track - was heading south from Warsaw to Krakow. Maintenance work was being done on the tracks before the accident happened, officials said.

Polish President Bronislaw Komorowski also visited the site on Sunday.