Police launched a late-night operation Sunday, Nov. 17 to try and flush about 200 protesters out of a university campus on a day of clashes in which an officer was hit in the leg with an arrow and massive barrages of tear gas and water cannons were fired.

Riot police began moving in on one group of protesters outside the campus after issuing an ultimatum for people to leave the area. They used tear gas and water cannons on a resistant crowd wearing raincoats and carrying umbrellas.

Protesters used bows and arrows earlier in the day, and one arrow struck a media liaison officer in the calf. Photos on the department’s Facebook page show the arrow sticking out of the back of the officer’s leg through his pants.

A protestor prepares to fire a bow and arrow during a confrontation with police at the Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. (AP Photo/Kin Cheung)
A protester prepares to fire a bow and arrow during a confrontation with police at the Hong Kong Polytechnic University in Hong Kong, Nov. 17, 2019. (Kin Cheung/AP Photo)

As riot police moved in from all sides, some protesters retreated inside Hong Kong Polytechnic University while others set fires on bridges leading to it.

A huge blaze burned along much of a long footbridge that connects a train station to the campus over the approach to the Cross-Harbor Tunnel, a major road under Hong Kong’s harbor that has been blocked by the protesters for days.

The use of bows and arrows, along with a gasoline bombs launched with catapults, threatened to escalate the violence in the more than five-monthlong anti-government movement. Protesters are trying to keep the pressure on Hong Kong leaders, who have rejected most of their demands.

Protestors react as police fire tear gas at Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. Police fired tear gas Sunday at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed in the morning. (AP Photo/Achmad Ibrahim)
Protesters react as police fire tear gas at Hong Kong Polytechnic University in Hong Kong, on Nov. 17, 2019. Police fired tear gas Sunday at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed in the morning. (Achmad Ibrahim/AP Photo)

The protests were sparked by proposed legislation that would have allowed the extradition of criminal suspects to the mainland. Activists saw it as an erosion of Hong Kong’s autonomy under the “one country, two systems” formula implemented in 1997, when Britain returned the territory to China.

The bill has been withdrawn, but the protests have expanded into a wider resistance movement against what is perceived as the growing control of Hong Kong by Communist China, along with calls for full democracy for the territory.

Several hundred people formed a human chain on Sunday in central Hong Kong in a peaceful rally in support of the movement.

A protestor hurls a molotov cocktail during a confrontation with police at the Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. Police have fired tear gas at protesters holding out at the Hong Kong Polytechnic University as overnight clashes resumed in the morning. (AP Photo/Kin Cheung)
A protester hurls a Molotov cocktail during a confrontation with police at the Hong Kong Polytechnic University in Hong Kong, on Nov. 17, 2019. Police have fired tear gas at protesters holding out at the Hong Kong Polytechnic University as overnight clashes resumed in the morning. (Kin Cheung/AP Photo)

Azaze Chung, a university student, said the government should respond to the protesters’ demands, not just use force against them.

Police and protesters faced off all day outside Polytechnic after a pitched battle the previous night in which the two sides exchanged tear gas and gasoline bombs that left fires blazing in the street.

A large group of people arrived in the morning to try to clean up the road but were warned away by protesters. Riot police shot several volleys of tear gas at the protesters, who sheltered behind a wall of umbrellas and threw gasoline bombs into nearby bushes and trees, setting them on fire.

Police spray blue-dyed liquid from an armored vehicle during a confrontation with protestors at the Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. Police fired tear gas and water canons at protesters holding out at the Hong Kong Polytechnic University as overnight clashes resumed Sunday, and opposition lawmakers criticized the Chinese military for joining a cleanup to remove debris from streets. (AP Photo/Vincent Yu)
Police spray blue-dyed liquid from an armored vehicle during a confrontation with protesters at the Hong Kong Polytechnic University in Hong Kong, on Nov. 17, 2019. (Vincent Yu/AP Photo)

The protesters held their ground for most of the day, as water cannon trucks drove over bricks and nails strewn by protesters to spray them at close range—some with water dyed blue to help police identify protesters afterward.

Protesters began retreating into the university near sunset, fearing they would be trapped as police fired tear gas volleys and approached from other directions. The protesters have barricaded the entrances to the campus and set up narrow access control points.

They are the holdouts from larger groups that occupied several major campuses for much of last week.

Protestors react during a confrontation with police at the Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. Police fired tear gas at protesters holding out at the Hong Kong Polytechnic University as overnight clashes resumed Sunday, and opposition lawmakers criticized the Chinese military for joining a cleanup to remove debris from streets. (AP Photo/Achmad Ibrahim)
Protesters react during a confrontation with police at the Hong Kong Polytechnic University in Hong Kong, on Nov. 17, 2019. Police fired tear gas at protesters holding out at the Hong Kong Polytechnic University as overnight clashes resumed Sunday, and opposition lawmakers criticized the Chinese military for joining a cleanup to remove debris from streets. (Achmad Ibrahim/AP Photo)

Another group threw bricks in the street to block a main thoroughfare in the Mongkok district, as police fired tear gas to try to disperse them. The disruption to Nathan Road traffic may have been an attempt to distract police during the standoff at Polytechnic.

Opposition lawmakers criticized the Chinese military for joining a cleanup to remove debris from streets near Hong Kong Baptist University on Saturday.

Dozens of Chinese troops, dressed in black shorts and olive drab T-shirts, ran out in loose formation and picked up paving stones, rocks and other obstacles that had cluttered the street.

Protestors react as police fire tear gas at Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. Police have fired tear gas at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed in the morning. (AP Photo/Ng Han Guan)
Protesters react as police fire tear gas at Hong Kong Polytechnic University in Hong Kong, on Nov. 17, 2019. Police have fired tear gas at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed in the morning. (Ng Han Guan/AP Photo)

The military is allowed to help maintain public order, but only at the request of the Hong Kong government. The government said that it had not requested the military’s assistance, describing it as a voluntary community activity.

The Education Bureau announced that classes from kindergarten to high school would be suspended again on Monday because of safety concerns. Classes have been canceled since Thursday, after the bureau came under criticism for not doing so earlier.

Protestors prepare to shoot bows and arrows during a confrontation with police at Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. Police fired tear gas at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed Sunday, and opposition lawmakers criticized the Chinese military for joining a cleanup to remove debris from streets. (AP Photo/Kin Cheung)
Protesters prepare to shoot arrows during a confrontation with police at Hong Kong Polytechnic University in Hong Kong, on Nov. 17, 2019. (Kin Cheung/AP Photo)
Protestors use an improvised slingshot during a confrontation with police at Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. Police fired tear gas at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed Sunday, and opposition lawmakers criticized the Chinese military for joining a cleanup to remove debris from streets. (AP Photo/Kin Cheung)
Protesters use an improvised slingshot during a confrontation with police at Hong Kong Polytechnic University in Hong Kong, on Nov. 17, 2019. Police fired tear gas at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed Sunday.  (Kin Cheung/AP Photo)
A protestor reacts as police fire tear gas at Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. (AP Photo/Kin Cheung)
A protester reacts as police fire tear gas at Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. (Kin Cheung/AP Photo)
Protestors react as police fire tear gas at Hong Kong Polytechnic University in Hong Kong, Sunday, Nov. 17, 2019. Police have fired tear gas at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed in the morning. (AP Photo/Ng Han Guan)
Protesters react as police fire tear gas at Hong Kong Polytechnic University in Hong Kong, on Nov. 17, 2019. Police fired tear gas at protesters holding out at Hong Kong Polytechnic University as overnight clashes resumed in the morning. (Ng Han Guan/AP Photo)
An armored police vehicle catches fire after being hit by molotov cocktails thrown by protestors, at right, on a bridge over a highway leading to the Cross Harbour Tunnel in Hong Kong, Sunday, Nov. 17, 2019. A Hong Kong police officer was hit in the leg by an arrow Sunday as authorities used tear gas and water cannons to try to drive back protesters occupying a university campus and blocking a major road tunnel under the city's harbor. (AP Photo/Kin Cheung)
An armored police vehicle catches fire after being hit by molotov cocktails thrown by protesters, at the right, on a bridge over a highway leading to the Cross Harbor Tunnel in Hong Kong, on Nov. 17, 2019. (Kin Cheung/AP Photo)
Protestors stand amid smoke on a bridge over a highway leading to the Cross Harbour Tunnel in Hong Kong, Sunday, Nov. 17, 2019. A Hong Kong police officer was hit in the leg by an arrow Sunday as authorities used tear gas and water cannons to try to drive back protesters occupying a university campus and blocking a major road tunnel under the city's harbor. (AP Photo/Vincent Yu)
Protesters stand amid smoke on a bridge over a highway leading to the Cross Harbor Tunnel in Hong Kong, on Nov. 17, 2019. (Vincent Yu/AP Photo)