WARNING: This story contains a video some may find distrubring.

HONG KONG -- Following a day of violence in which one person was shot by police and another set on fire, Hong Kong's leader pledged Monday to "spare no effort" to halt anti-government protests that have wracked the city for more than five months.

The comments by Carrie Lam are likely to fuel speculation that harsher legal and police measures may be in the works.

"I do not want to go into details, but I just want to make it very clear that we will spare no effort in finding ways and means that could end the violence in Hong Kong as soon as possible," Lam told reporters.

Lam also refused to accept the protesters' demands for political concessions.

"If there is still any wishful thinking that, by escalating violence, the Hong Kong SAR government will yield to pressure to satisfy the so-called political demands, I am making this statement clear and loud here: That will not happen," Lam said, using the initials for Special Administrative Region, which describes the city's status as a semi-autonomous Chinese territory.

"These rioters' actions have far exceeded their demands, and they are enemies of the people," she said.

Following Lam's comments, confrontations between protesters and police continued into the night, with black-clad demonstrators torching at least one vehicle and blocking an intersection in the Mongkok district that has been the scene of many clashes. A taxi driver was taken away by ambulance with head wounds, although it wasn't immediately clear how he had been injured.

The violence is likely to further inflame passions in Hong Kong after a university student who fell from a parking garage during an earlier protest succumbed Friday to his injuries and police arrested six pro-democracy lawmakers over the weekend on charges of obstructing the local assembly during a raucous May 11 meeting. All were freed on bail.

China's ruling Communist Party has also indicated it may try to find a way to enact anti-subversion laws in the territory. Such measures were shelved previously due to public opposition.

While Beijing has dismissed reports it may replace Lam next year, the party last week issued a statement saying it would "perfect" the system to appoint and dismiss Hong Kong's leader and top officials.

In a widely distributed video, a police officer is shown shooing away a group of protesters at an intersection Monday morning, then drawing his gun on a masked protester in a white hooded sweatshirt who approaches him.

As the two struggle, another protester in black approaches, at whom the officer points his gun. He then fires at the stomach area of the second protester, who falls to the ground. The officer appeared to fire again as a third protester in black joined the tussle.

The protester in white flees up a nearby stairway, and the officer and a colleague pin the two in black to the ground.

Police said only one protester was hit and that he was undergoing surgery. The Hong Kong hospital authority said the person was initially in critical condition but was stable after surgery.

It was the second protester shot since the demonstrations began in early June, although police have repeatedly drawn their firearms to ward off attacks. Police said they arrested more than 260 people on Monday, adding to the more than 3,300 arrests since the movement erupted in June.

Few details were available about the burning incident in the Ma On Shan neighbourhood. Video posted online shows the victim arguing with a group of young people before someone douses him with a liquid and strikes a lighter. The man was reported in critical condition.

Police fired tear gas and deployed a water cannon in parts of the city and charged onto the campus of Chinese University, where students were protesting. Online video also showed a policeman on a motorcycle riding through a group of protesters in an apparent attempt to disperse them.

Police spokesman Tse Chun-chung said the shooting, burning and motorcycle incidents were all under investigation, but defended the officers' actions as necessary for their own safety. Tse said two people were arrested in the shooting incident, including the person shot, but no one has yet been detained over the burning.

Protesters built barricades and blocked roads at about 120 locations across the city of 7.4 million and demonstrations were still ongoing, Tse said.

"Continuing this rampage is a lose-lose situation for Hong Kong. Everyone is a loser," Tse said.

Rail service was partly suspended because of fires and obstacles on the tracks and windows were smashed at a branch of the state-owned Bank of China. Large parts of the downtown business district were closed to traffic as protesters surrounded by onlookers engaged in a standoff with police.

The protests began over a proposed extradition law and have expanded to include demands for greater democracy and police accountability. Activists say Hong Kong's autonomy and Western-style civil liberties, promised when the former British colony was returned to China in 1997, are eroding.

The video of the shooting was posted on Facebook by Cupid Producer, an outlet that started last year and appears to post mostly live videos related to local news.

The shooting occurred in a crosswalk at a large intersection strewn with debris that had backed up traffic in Sai Wan Ho, a neighbourhood on the eastern part of Hong Kong Island.

In a statement, the Hong Kong government said police had been responding to vandalism and disruptions of traffic, including protesters throwing heavy objects onto roads from above.

"During police operations, one police officer has discharged his service revolver, one male was shot," the statement said, adding that officers also drew their guns in the Shatin and Tung Chung neighbourhoods.

The statement denied what it called online rumours that police had been ordered to "recklessly use their firearms," calling the allegation "totally false and malicious."

"All police officers are required to justify their enforcement actions," the statement said.

A patch of what looked like dried blood could be seen in a cordoned-off area after the shooting, as onlookers shouted insults at the police.

Masked protesters continued trying to block other intersections in the area, but police chased them away with pepper spray, hitting some bystanders as well.

On Sunday, police fired tear gas and protesters vandalized stores at shopping malls during demonstrations. They targeted businesses whose owners are seen as pro-Beijing and also damaged the Sha Tin train station.

Police said they arrested at least 88 people on charges including unlawful assembly, possession of an offensive weapon, criminal damage and wearing masks at an unlawful assembly.

Hong Kong is preparing for Nov. 24 district council elections that are seen as a measure of public sentiment toward the government. Pro-democracy lawmakers accuse the government of trying to provoke violence to justify cancelling or postponing the vote.