The Ministry of Railways said on Monday that the derailment of train K127 from Xi'an to Changchun the day before was caused by signal failure due to theft of a cable box.
The train collided with a cargo train between the northeastern cities of Changchun and Dalian at 7:52 PM, causing five carriages to derail.
The ministry source said a cable box on the Xinchengzi-Xintaizi section of the track, where the accident occurred, had been stolen.
Train staff were unaware of the situation so did not stop the train.
Five passengers were confirmed dead and 30 others injured, according to latest information from the ministry, though six people had previously been reported killed.
The accident caused stoppages on the Changchun-Dalian line, but normal operations were resumed on Monday afternoon.
(Xinhua News Agency August 2, 2005)