BEIJING - China will resume the operation of all 54 bullet trains previously recalled over safety concerns starting from Dec 12, the Ministry of Railways (MOR) said Thursday.

A new operation schedule for the Beijing-Shanghai high-speed railway, on which the CRH 380BL trains run, will take effect at midnight on Dec 11, an MOR official told Xinhua on condition of anonymity.

The MOR said last month problems with the bullet trains had been fixed after three months of modifications and repeated tests and that the trains would gradually be put back in use from Nov 16.

In line with the new schedule, there will altogether be 92 pairs of trains serving the Beijing-Shanghai high-speed railway, said the official.

Among them, 65 pairs of trains will run at a speed of 300 km per hour, up from the current 39 pairs, while 27 pairs will run at 250 km per hour, up from 25 pairs, he said.

China's state-owned train maker, China CNR Corp (CNR), announced on August 12 the recall of 54 trains it supplied for the high-speed rail link between Beijing and Shanghai. The trains, all CRH 380BL models, were to be investigated for equipment failure and modified accordingly.

The recall came three weeks after 40 people were killed in a high-speed train crash in the eastern Zhejiang province, an incident which triggered public fury in China.

Before the recall, Beijing-based CNR had decided to suspend the delivery of the CRH 380BL trains, citing flaws in their automatic braking systems.

CNR blamed most of the problems on defects with outsourced components.

The Tangshan Railway Vehicle Co Ltd., a CNR subsidiary and one of the manufacturers of the CRH 380BL models, said the trains that have resumed service are in good operation.

Quality-tracking and after-sale services will be improved to ensure safety of the trains, Zhao Hu, an official with the company, told Xinhua.