The conflict occurred late Wednesday after an argument between local police conducting checks on foreign workers turned into a scuffle involving more than 200 Chinese labourers.

Russian media said about 20 workers were hurt, some seriously.

The migrants, working on a building site, were reported to be "very emotional" when asked to show their documents, and some of them allegedly appeared to be drunk, said Xinhua. The report said they quarrelled with the police, refusing to show their papers. Two were arrested.

Chinese Foreign Ministry spokesman Kong Quan on Saturday urged the Russian authorities to investigate the incident and ensure it was not repeated.

He said the Chinese Consulate General in Khabarovsk had made immediate representations to the Russian authorities on hearing about it, and the foreign ministry had called Russian embassy officials in Beijing [Images] on Friday.

"The issue has aroused great concern from the Chinese Government," Kong said, urging that the troublemakers be punished and the injured Chinese treated.

Reports said when the police revisited the construction site the following day, all workers had legitimate documents. Other building sites with foreign workers were also targeted for inspections in the city, said Xinhua.

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