A Chinese high-speed train killed four maintenance workers after a communication failure, state media reported Tuesday, the latest fatal incident on the country's flagship rail network.

The D28 train was at least 11 minutes behind schedule when it hit five railway personnel maintaining and cleaning the track during what was supposed to be their "working hour window", the 21st Century Business Herald said.

Four of the staffers, all under 30 and two of them new university graduates, were killed and one injured, said the report, which cited an internal railway circular.

China's high-speed rail network is the largest in the world, and seen by Beijing as a symbol of the country's advance.

But the expansion -- which has cost hundreds of billions of dollars -- has seen a series of scandals and widespread allegations of corruption, with accusations that safety has been compromised for speed.

The incident, between Taian and Panjin North in the northeastern province of Liaoning on Friday, was the latest fatal accident on the network.

At least 40 people were killed in a high-speed train crash near Wenzhou in Zhejiang province in July 2011.

Ex-railway minister Liu Zhijun, who campaigned for and oversaw the expansion of the high-speed network, was given a suspended death sentence in July for taking 64.6 million yuan ($10.6 million) in bribes.