HONG KONG (AP) — Clad in gas masks along with their formal white school uniforms, tens of thousands of students in Hong Kong boycotted the first day of classes Monday as part of a citywide strike following a violent weekend of demonstrations.

High school students added gas masks, goggles and hard hats to their traditional uniforms, while university pupils crowded into a square at the Chinese University of Hong Kong. Workers also participated in their own rally at a public park, braving strong winds and storm clouds as a typhoon threatened.

Nearly three months of youth-dominated protests — calling for democracy and an independent inquiry into police conduct — will be tested as classes resume with the end of the summer break in the semiautonomous Chinese territory.

The young protesters strove to demonstrate their continued determination with Monday’s school boycott, the first of a planned two-day strike.

Jacky So, president of the Chinese University of Hong Kong’s student union, said 30,000 students attended a rally on campus. They dressed in black and wore face masks, waving banners for their student associations and black signs with the Chinese character for “Strike.”

Separately, high school students who were skipping class rallied in Edinburgh Place, a public square in Hong Kong’s central business district. Teenagers spoke to the crowd from a stage with a backdrop that read: “With no future, there’s no need to go to class.”

At St. Francis’ Canossian College, uniformed students kneeled in a line and held up hand-painted signs that read, “The five major demands: Not one is dispensable.” The elite girls’ school is where Hong Kong Chief Executive Carrie Lam was educated.

Hong Kong Education Secretary Kevin Yeung said he hoped students would stay in class.

“Schools should not be used as places for political demands or exercising pressure,” he said at a government briefing.

The protesters’ demands include dropping charges against more than 1,000 people who have been arrested and formally withdrawing an extradition bill that would allow Hong Kong residents to be sent to mainland China to stand trial. The appeals are undergirded by a sense among some Hong Kong residents that the Communist Party-ruled mainland government has been eroding the autonomy and civil liberties promised when the former British colony was returned to China in 1997.

Some demonstrators disrupted the morning commute on Monday by blocking train doors, attempting to evade riot police who were hot on their heels by moving quickly between multiple public transit stations.

Officers at Lok Fu station hit protesters with batons and arrested one. Three others were arrested at Lai King station.

On Sunday, the MTR Corp. suspended train service to the airport after several hundred protesters gathered there following calls online to disrupt transportation. They blocked buses arriving at the airport but police in riot helmets kept them out of the terminal. Some protesters hurled bricks and metal poles onto the tracks of the Airport Express rail line, police said, prompting train services to be suspended and forcing some travelers to walk some distance to the airport.

Late at night Saturday, video from Hong Kong broadcaster TVB showed police on the platform of Prince Edward subway station swinging batons at passengers who backed into one end of a train car behind umbrellas. The video also shows pepper spray being shot through an open door at a group seated on the floor while one man holds up his hands.

Police officers said at a briefing Monday that they rejected accusations that they “beat up” ordinary citizens without first confirming their identities. They said they specifically targeted those who they believed to be rioters, including those who had changed out of their black protester outfits, and arrested 63 people on suspicion of illegal assembly and possessing explosives and offensive weapons.

Radical protesters have “hijacked the name of justice,” Assistant Commissioner of Police Mak Chin-ho said Monday. “The biggest victims are the citizens of Hong Kong.”

Clashes between police and protesters have become increasingly violent, as the self-described “front-line” demonstrators use gasoline bombs and throw rods at officers. Authorities in turn have employed water cannons, tear gas, rubber bullets and batons.

The protesters say that a degree of violence is necessary to get the government’s attention after peaceful rallies were futile. Lam’s administration, however, maintains that the violence must first end before any fruitful dialogue can begin.

“We always say that we must stop the violence right away, and then kick off the dialogue,” said Administration Secretary Matthew Cheung Kin-Chung.

___

Associated Press journalists Alice Fung and Raf Wober in Hong Kong and Yanan Wang in Beijing contributed to this report.