BEIJING - A high-ranking work safety official on Thursday ruled out the possibility of natural disaster causing July's high-speed train crash that left 40 dead and 191 others injured.

"Now I can say for sure that this is not a natural disaster," Huang Yi, the spokesman and a leading official with the State Administration of Work Safety, said on Thursday during an online chat hosted by people.com.cn, the online arm of People's Daily.

"Rather it's a very serious railway traffic accident," he stressed.

On July 23, two high-speed trains crashed in Wenzhou city in East China's Zhejiang province. Previous media reports said authorities blamed the accident on lightning that hit the signal system and knocked the system vital for safety out of service.

Huang added that the railway authorities had also pointed out loopholes and deficiencies in safety management, which had emerged in the accident.

The State Council, or China's Cabinet, set up an investigation team shortly after the accident occurred, with Luo Lin, director of the Sate Administration of Work Safety, being appointed as leader of the team.

Since its establishment, the State-level team's work has been closely watched by the public. But the team has not released any further information about the progress of its investigation in the past week.

In Thursday's online talk, Huang said the team's work, including the collection of evidence, analysis of wreckage and questioning of witnesses, is under way.

The team would also simulate the deadly train crash if needed, added Huang.

"We will make it public as soon as the result (of the investigation) comes out," he said.

On July 28, Luo said at a meeting of the team members that the team will try its best to release the result in mid-September.

At the same meeting, An Lusheng, head of the Shanghai Railway Bureau that administrates railways in Wenzhou, admitted that railway employees on duty in the city had failed to be aware of the breakdown of the signal device in the wake of the lightning strikes.

It also turned out that they did not know the function of the device's key part, said An.