Hong Kong  - China was criticized Saturday over the treatment of three Hong Kong television journalists who claimed they were detained and beaten up while covering protests in the far western city of Urumqi.

Hong Kong's Beijing-appointed leader, Donald Tsang, said he was "deeply concerned" at reports about their treatment at the hands of armed police Friday as they covered unrest in the ethnically divided city.

Senior Beijing-based reporter for Hong Kong channel TVB Lam Tza-ho and his cameraman Lam Wing-chuan were tied up and held for hours during Friday's riots along with cameraman Lam Chun-wai from Hong Kong's Now cable TV channel.

TVB said the journalists were pushed to the ground by military police, bound, punched, kicked and beaten with a baton before being taken to a police station and detained. No reason was given for their arrest.

All three had credentials to work as journalists in mainland China and press passes for Urumqi but appeared to have been caught up in a fast-changing official approach to the media by Chinese officials as violence in the region escalates.

TVB said it had lodged a complaint over the handling of its journalists with Chinese officials in Hong Kong and with the All China Journalists Association.

Chief Executive Tsang told journalists he had instructed the Hong Kong government's Beijing office to investigate the incident and offer assistance to the journalists if needed.

Hong Kong reverted to Chinese rule in 1997 after 156 years as a British colony but has a mini-constitution guaranteeing freedom of the press along with judicial and political autonomy. (dpa)