At least 30 people were feared dead on Monday in the eastern Spanish city of Valencia after an underground metro train derailed and turned over in the city centre, an official said.
About a dozen people were reported seriously injured. The accident prompted the evacuation of 150 people from the underground.
The accident occurred as thousands of Roman Catholics had gathered in Valencia for the World Meeting of Families, which is to culminate with the visit of Pope Benedict XVI over the weekend.
The train derailed in a bend soon after leaving Jesus station. Reports said a part of the tunnel's roof might have collapsed.
The injured were being taken to various hospitals. A makeshift hospital was also set up in front of the underground station.
The area was sealed off to traffic. Service was suspended on two underground lines.