China's Ministry of Railways (MOF) said late Friday it will draw lessons from the deadly bullet train crash and take concrete measures to improve safety management.

The crash revealed that safety control in some railway enterprises remains weak. Railway personnel must improve their on-site control and emergency response abilities, the ministry said in a question and answer dispatch to Xinhua.

A high-speed train rammed into a stalled train near the city of Wenzhou in east China's Zhejiang Province on Saturday, leaving 40 people dead and 191 injured.

The tragedy was caused by "serious design flaws" in railway signaling equipment, an official from the Shanghai Railway Bureau said Thursday morning.

The ministry rebutted speculations that it tried to bury parts of the derailed trains under the viaduct where the accident happened to hide evidence.

Three carriages were squeezed together after the crash. In order to allow rescuers to thoroughly search the carriage which was seriously distorted and stuck in the middle, workers had to use large-tonnage truck cranes to remove the carriages on both ends, the ministry said.

The debris was put in a pit to make way for the truck cranes, the ministry said, adding that none of the debris and derailed carriages were buried.

After rescue operations were over, the carriages and debris were taken to the west railway station of Wenzhou for investigation, it said.

The ministry said it has launched a two-month safety overhaul in the railway system starting from July 24 to eradicate protruding safety problems and risks.

Special efforts will be made to ensure safety of the signal system, it said, adding that efforts will also be made to improve emergence response system.