The train derailed early Monday was running over 100 kilometers per hour, much faster than the 70 kph upper limit, according to Japanese media reports on Tuesday.

The finding boosted speculation that speeding was to blame for the bloody accident. The initial report said the derailment might result from a collision with a car at the crossing.

Investigators also are looking into marks on the track, suspecting that the train might run over stones possibly placed by someone on the rail.

The accident has killed 76 people and left more than 450 injured. Rescuers believe that there are still 10 to 20 people trapped into the first two carriages about 36 hours after the derailment.

The seven-car train with about 580 people aboard rammed into an apartment building nearby after the derailment in Amagasaki, Hyogo Prefecture. The two front cars were badly damaged, making it great difficult for rescue workers to reach the remaining passengers.

Local police determined the train's speed after having found its speed recording device, the reports said.

Many survivors also said in TV reports that they felt the train was running unusually fast.

The train was one and half minutes behind schedule when it started at the last station. The 23-year-old driver missed the proper stop position by 40 meters and had to back up, the West Japan Railway Co. said on Tuesday. The company said that the conductor of the train conspired with the driver to report to the command center that the overrun was only eight meters.

The train theoretically would derail if its speed exceeded 130 kph but it was designed to have a top speed of 120 kph.

The death toll made itself the most serious in Japan since May 14, 1991, when 42 were killed and 527 injured in a collision of two trains in west Japan.

(Xinhua News Agency April 27, 2005)