HONG KONG — Across Hong Kong’s university campuses, students and their supporters are bracing for police confrontations in increasingly elaborate ways: constructing Molotov cocktail assembly lines, erecting catapults that use helmets to launch projectiles, and building walls made of brick and mortar or crosshatched bamboo.
As riot police officers bombarded the Chinese University of Hong Kong on Tuesday with rapid-fire tear gas and stinging liquid, a secluded haven for learning suddenly looked more like a battlefield. Now, students across the city said, they are being pushed to defend themselves in more radical ways.
“They are insulting the institution of universities. This is a holy place for us to learn. It’s not a place for them to ruin,” said Anna Foy, a 23-year-old graduate student. “I used to just Photoshop posters, protesting in air-conditioning. But now I have evolved into someone who goes to the front line.”
After five months of unrest, tensions rose in the past week, first after the death of a student demonstrator who fell from a parking garage, and then after the police shooting of an unarmed protester. Demonstrators have disrupted the city’s transportation system in recent days in an effort to force the government to respond to their demands, including accountability for the police.
As the police crack down, students have found themselves in previously unimaginable situations.
“I didn’t think I would be mixing these chemicals with my own hands, but I am here to learn,” said Jacqueline Kwok, a 19-year-old student at the Hong Kong Polytechnic University, or PolyU, surrounded by plastic funnels, rolled towels and glass bottles. The pungent smell of chemicals filled the air as another protester tested a freshly made gasoline bomb by hurling it into a drained swimming pool, flames licking the blue tiles as the bottle smashed.
Other students said they planned to make smoke bombs that would cause less bodily harm, but whose sulfuric odors would also deter police advances.
On the edges of campuses, black-clad protesters stalked rooftops and makeshift watchtowers, keeping a wary eye out for undercover officers and potential snitches. Visitors who wanted to pass through had to show either student or press cards at “customs” stands, and present their belongings to be inspected.
Protesters scattered nails and bricks stacked like mini Stonehenges, to slow down police vehicles should they try to clear the roads. And small groups roamed with bows and arrows, a few even practicing with flames.
Ken Chan, a 17-year-old high school student and archery hobbyist, said: “I know this is really extreme and risky. I would consider shooting arrows as a final resort, if I could protect the people of Polytechnic University and to protect Hong Kongers. This is really extreme.”
University leaders said they were alarmed that violent clashes — and preparations for future ones — had reached campus grounds previously untouched during the months of unrest, and that large numbers of outside protesters were now occupying its buildings and fields.
“Our campus has been turned into a scene of disorder,” PolyU said in a statement, urging students and staff members to stay away and pleading for the outside protesters to leave. Classes were being held online.
At the Chinese University of Hong Kong on Friday night, protesters evacuated the campus after a van was set on fire and explosions were heard.
John Tse, police chief superintendent, said on Wednesday that the force suspected that C.U.H.K. was being used as a “weapon factory.” He added that the use of tear gas, rubber bullets and beanbag rounds against students was justified on those grounds.
Fearing a new incursion by the police, many supporters of the protesters, including alumni, flocked to the campuses, leaving bags of food and supplies. “We are very worried about the students, so we wanted to come back and check on them,” said Karen Chan, a 30-year-old social worker and graduate of PolyU.
The campus’s cafeteria had the air of a disaster bazaar, with overflowing boxes of bottled water, gas masks, goggles and paper towels, organized by category. In the kitchens, volunteer cooks made simple meals of white rice, canned meat and noodles.
“When it was quiet, I started making chicken-egg sandwiches for protesters so that they can eat something yummy, not just ramen, ramen and ramen,” said Ryan Fa, a 17-year-old volunteer medic.
Elite universities like C.U.H.K. and the University of Hong Kong have even earned nicknames like Riot U and Revolution University.
Coco Wong, a C.U.H.K. student, said the name Riot U reflected the “wild” nature of her classmates.
“We of Riot U have people with all sorts of knowledge and ability,” she said. “When our home turf is being invaded, we can only rush to the front and fight back.”