Pro-democracy lawmakers in Hong Kong interrupted a Beijing official mid-speech on Monday as he sought to explain the benefits of new Chinese voting reforms that were announced over the weekend. The government reforms would restrict Hong Kong's ability to freely elect a new leader.

The lawmakers shouted slogans at Li Fei, a deputy secretary general of the Standing Committee of the National People's Congress (NPC), as he delivered a speech about the mainland's decision.

Some stood on chairs in the venue and held signs reading "Shameful" and "Loss of faith," in reference to China's perceived loss of credibility after breaking earlier promises of greater electoral freedom.

Demonstrators gathered in front of the government headquarters in Hong Kong's Tamar Park on Sunday night for a pro-democracy protest. The demonstration was called in response to a ruling from Beijing on plans for direct elections of Hong Kong's Chief Executive.

Outside the building, chaos ensued as police used pepper spray on members of a radical pro-democracy activist group who were trying to enter the premises and attempting to break the metal barriers surrounding the conference center.

China has granted Hong Kong unprecedented autonomy and expansive freedoms since it was handed back to the mainland in 1997 following 150 years of British colonial rule. The southeast Asian financial hub has been under the mainland policy of "one country, two systems" since that time, and its leadership has been elected by a committee made up of mostly pro-Beijing financial and business tycoons.

Hong Kong was set to hold its first democratic popular vote elections in 2017, but these plans were capsized on Sunday with China's announcement that it would be ruling out open nominations for candidates.

The NPC said candidates would be limited to two or three contenders who must first be majority-approved by a nominating panel similar to the committee of Beijing loyalists previously charged with overseeing Hong Kong's leadership. The move essentially precluded opposition democrats from entering the ballot.

Hong Kongers gathered in front of the government headquarters in Tamar Park on Sunday night for a pro-democracy protest. The demonstration was called in response to a ruling from Beijing on plans for direct elections of Hong Kong's Chief Executive.

The anticipated announcement will likely be the catalyst for a series of planned rallies held by democracy activists in coming days. In particular, a group called Occupy Central has threatened mass demonstrations on an unknown date that would lock down Hong Kong's financial district, if China fails to grant a full and free democratic election.

Li said that lawmakers must not give in to the activists' demands.

"Occupy Central is an illegal activity. If we give in, it will trigger more illegal activities," he said.

Li also said that if Hong Kong lawmakers rail too heavily against the decision and ultimately reject it, the NPC would scrap allowances for a popular election and the region's next leadership would again have to be chosen by a small committee.