UNITED NATIONS (Sputnik) - UN Secretary-General Antonio Guterres is following the protests in Hong Kong and has called on all sides to exercise restraint and commit to non-violence and dialogue, UN Spokesperson Stephane Dujarric said in a news briefing on Monday.

"The Secretary-General has been following the events that have been taking place in Hong Kong. He reiterates the importance of respect for the right to peaceful protest and freedom of assembly and expression as well as the commitment by all sides to dialogue, non-violence and restraint", Dujarric said.

Earlier in the day, the anniversary of the city’s 1997 return to Chinese rule, hundreds of mainly young masked protesters set up barricades on several streets in the city-state, resulting in clashes with police who used batons and pepper spray to disperse crowds.

Some of the protesters then tried to break into the Legislative Council (LegCo) building, smashing windows with objects.

The LegCo Secretariat for the first time declared an unprecedented red security alert and ordered the building evacuated.

Mass rallies erupted in Hong Kong in early June as authorities considered adopting a bill that would allow the autonomous Chinese region to extradite suspects to jurisdictions with which it did not have an extradition agreement, including mainland China, Taiwan and Macao.

Pressured by the protests, the government indefinitely suspended the bill, while Hong Kong chief executive Carrie Lam issued a public apology. However, the protesters are demanding the complete withdrawal of all extradition amendments.

The Hong Kong region, which enjoys significant autonomy in China except in foreign and defense policy, has a legal system different from mainland China. Opponents of the proposed bill claim it would be "the death" of Hong Kong as any human rights activist or member of the non-governmental organization whose activity does not please Beijing will risk persecution.