Hong Kong's first bullet train will glide out of a sleek harbor-front railway station bound for mainland China on Saturday, launching a new era of integration — and raising fears among some for the territory's cherished freedoms.

Unlike other cross-border connections, the $11 billion train project has stoked considerable controversy, with Hong Kong, a former British colony, having had to concede part of its jurisdiction to China for the first time.

Passengers entering the modernist building will have their documents stamped by Chinese immigration officers and will be subject to Chinese law while zipping across Hong Kong at 200 kph (120 mph) to the mainland.