Suspects believed to be responsible for beating to death a reporter who was investigating operation of a coal mine in north China's Shanxi Province are being tracked by police, local authorities reported Wednesday.

The Shanxi Provincial Security Bureau has dispatched over 70 officers to investigate and they've made some breakthroughs, officials said, without elaborating.

"Lan Chengzhang, who worked for the Beijing-based China Trade News and a taxi driver he'd hired, were attacked on January 10 at a coal mine in Hunyuan county of Datong city," a local police official said. "The coal mine owner sent more than 20 thugs in their twenties, from Datong, to beat up the two men," he explained. 

Lan died from brain injuries in hospital and his driver is receiving treatment for two broken legs.

The incident has provoked online debate from Chinese netizens over the reporter's death. Accusations of blackmail by local officials have poured fuel on the fire with them accusing Lan of posing as a journalist in order to extort money from the coal mine. It doesn't have a production license.

"It's inappropriate to discuss whether or not Lan was a registered journalist now. The most important thing is to arrest the assailants and deal with them according to the law," said Da Li, a local TV reporter. 

Datong city government spokesman, Gu Shengming, said Lan had no press card and his interview was not officially approved. However, he admitted that Lan had been hired by the newspaper.

"Lan has been temporarily hired by the newspaper's branch in Shanxi for a short period. It's still not clear when he went to the coal mine or how the incident happened," Gu said. "A vice president of the newspaper has arrived in Datong to investigate the case," he added. 

(Xinhua News Agency January 18, 2007)