China's government ruled that candidates for Hong Kong's top leadership post must be approved by a committee heavily loyal to Beijing, providing a clear demarcation of how far it will allow democracy to proceed in the territory.

The decree capped months of blunt reminders from Beijing of who is in charge in the former British colony, and quickly drew ire from pro-democracy voices in Hong Kong, who have threatened a mass civil-disobedience campaign if they aren't offered "genuine choice" in 2017 elections.

"Hong Kong people have the reason to believe they have been betrayed," said Alan Leong, a Hong Kong pro-democracy legislator. "We cannot be the boss, we cannot have genuine choice," he said. Another lawmaker, Lee Cheuk Yan, said the fight for "true democracy" would continue.

Democracy activists in Hong Kong gathered Sunday evening outside the city's government headquarters, where police beefed up security and erected barricades. In pouring rain, hundreds of people sat banging pots and plastic containers and cheered the speakers. Benny Tai, one of the organizers of Occupy Central, said, "Hong Kong is now entering a new era—a new era of resistance."

Several in the crowd said they weren't surprised by the decision. "I knew it wasn't possible for Beijing to grant Hong Kong democracy, but I still have to fight," said 80-year-old Ng Hung. "I am here for the next generation."