Journalist Elkhan Mirzoyev, from Azerbaijan, said he was attacked on a train by a group of young men and a woman, who hit him with beer bottles.

Police are treating the crime as based on "ethnic, racial, religious hatred", according to news agency Itar-Tass.

Mr Mirzoyev, who appeared on NTV with a bandaged head on Monday, said a group had beaten him.

"One of them was a real skinhead with high boots, camouflage and a black jacket," he said. "He came up to me, sat and began to talk to me... Rather, he tried to explain why I should not live in Russia."

Ethnic groups in Russia have raised concerns about the rising number of apparently race-related attacks, BBC reports.