Hong Kong Secretary for Transport and Housing Frank Chan (R) shakes hands with Deputy Secretary-General of the Shenzhen Municipal People's Government Yang Xiuyou from mainland China during a handover ceremony at West Kowloon Terminus, Sept. 3, 2018.
Hong Kong Secretary for Transport and Housing Frank Chan (R) shakes hands with Deputy Secretary-General of the Shenzhen Municipal People's Government Yang Xiuyou from mainland China during a handover ceremony at West Kowloon Terminus, Sept. 3, 2018.

A new high-speed rail station linking Hong Kong and mainland China opened Tuesday under Chinese authority, raising new worries among Hong Kong residents of a further erosion of the territory's autonomy.

China formally took control of the new depot in Hong Kong's West Kowloon district during a quiet nighttime handover ceremony that was not announced until it was over. Hong Kong chief executive Carrie Lam denied that officials were being "sneaky" about the opening of the station, which will officially open on September 23.

Chinese authorities will conduct customs and immigration checkpoints at the new station, which will be subject to Chinese law and patrolled by mainland security officers.

Pro-democracy advocates say the new rail station is a further example of the mainland's tightening grip on the former British colony, which was granted a huge level of autonomy under the "one country, two systems" formula established when Beijing regained control of the territory in 1997.