Violence is again pushing Hong Kong on the verge of a very dangerous situation as rioters turned anti-government protests into a riot over the weekend.

The Hong Kong Police Force, the Hong Kong Special Administrative (HKSAR) government and pro-establishment legislators on Monday strongly condemned violent protesters who obstructed roads, vandalized shops and tunnel facilities, hurled Molotov Cocktail, bricks and other objects at police officers across Kowloon and the New Territories over the weekend.

During the operations, 21 police officers were injured and sent to the hospital. Police arrested 86 for offenses ranging from unlawful assembly and possession of offensive weapons to assaulting police officers, police said on Monday.

The weekend protests in Kwun Tong and Tsuen Wan ended up as a riot, seriously sabotaging the peace and putting local residents in those districts in danger.

Radical protesters willingly escalated violence despite their claimed peaceful assemblies, and they had set various types of traps, hurling weapons such as pellets, iron branches and shackles with bricks to the police, reporters and residents, Mak Chin-Ho, assistant commissioner of Hong Kong Police, who is responsible for operations, told a press briefing at police headquarters.

Some even threw Molotov Cocktail from the overpass to police on the ground. Several policemen were hurt, and the violent acts of protesters could have been fatal, Mak said.

On Sunday night, groups of protesters used ferrous and bamboo branches and guide boards to attack several policemen at the Sha Tsui Road, which injured policemen or even endangered their lives.

The policemen were present to deal with a criminal damage case, so they did not bring riot equipment but only round shields, batons, pepper spray and .38-caliber revolvers, said John Tse Chun-chung, chief superintendent of the Police Public Relations Branch, during the press briefing on Monday.

At that time, a group of protesters was trying to beat the policemen and one of them fell down, but was still being hit by protesters. Seeing their colleague in danger, some policemen chose the most suitable force - revolvers - at that moment after protesters ignored several warnings. As the situation went almost out of control, one of them fired a warning shot in the air, Tse noted.

The act of the police officer was "courageous and restrained" and his use of force "necessary and reasonable," he said.

Witman Hung Wai-man, principal liaison officer for Hong Kong at the Shenzhen Qianhai Authority, told the Global Times that the police have to protect themselves first before protecting public safety and security, and that the policeman firing a warning shot in the air rather than at civilians was "extremely restrained."

While some Hong Kong and Western media blamed the Hong Kong police for using excessive force, as footage showed a police officer kicking a resident who knelt between the police and protesters, Tse defended the police officer's act.

"The man was in the middle of the action where the police officer was holding a gun. The protesters still confronted the police, who had a broken shield and a gun. And the officer was injured after being stabbed by iron branches," Tse said, noting that to avoid greater danger, the officer chose to push the man away to place the situation under control.

Tian Feilong, an associate professor at Beihang University in Beijing and a member of the Beijing-based Chinese Association of Hong Kong and Macao Studies, noted that since the riots and violence are becoming normalized, the police should upgrade their equipment and tactics.

During the press conference organized by the Hong Kong Police Force, most Hong Kong local media and foreign media put their focus on the policemen pointing their guns at the rioters and journalists, and blamed the police for using weapons to threaten "people and journalists."

Tian stressed that in a color revolution, pressure from the press on the police and other law enforcement agencies is part of the tactics to try to overthrow the government and disturb public order. So, Hong Kong police should focus on law enforcement and not be pressured by biased media outlets.