Thousands of Hong Kong civil servants rallied on Friday night to support protesters and urge authorities to rebuild confidence in the government as escalating protests rock the Asian financial hub.

The rally is the first time government employees have promoted a demonstration in Hong Kong. The civil servants assembled peacefully with protesters in the heart of the business district, many in black masks to hide their identity.

“I think the government should respond to the demands, instead of pushing the police to the frontline as a shield,” said Kathy Yip, a 26-year-old government worker.

Police said they had arrested eight people, including a leading pro-independence leader, after seizing weapons and suspected bomb-making material in a raid.

A wave of protests is planned across Hong Kong this weekend, along with a mass strike on Monday across sectors such as transport, schools and businesses that could bring the city to a standstill.

The protests in Hong Kong, a former British colony that returned to China in 1997, pose one of the gravest populist challenges to Communist Party rulers in Beijing.

The protests against a now suspended extradition bill, which would have seen people sent for trial in mainland courts controlled by the Communist Party, widened to demand greater democracy and the resignation of Hong Kong’s leader Carrie Lam.

Under Chinese rule Hong Kong has been allowed to retain extensive freedoms, such as an independent judiciary, but many residents see the extradition bill as the latest step in a relentless march towards mainland control.

“At present the people of Hong Kong are already on the verge of collapse,” a group of civil servants said in an open letter to Lam.

“Hong Kong has always been well behaved and enjoys a high degree of freedom. It is a pity that we have seen extreme oppression …”

It asked Lam to respond positively to five public demands: complete withdrawal of the extradition bill; a halt to descriptions of the protests as ‘rioting’; a waiver of charges against those arrested; an independent inquiry and resumption of political reform.

The city’s 180,000 civil servants must remain politically neutral, the government said on Thursday.

“At this difficult moment, government colleagues have to stay united and work together to uphold the core values of the civil service,” it said in a statement.

More protests planned

Hundreds of medical workers also demonstrated on Friday to protest against the government’s handling of situation. Large-scale protests are planned for the weekend in Mong Kok, Tseung Kwan O and Western districts.

Clashes between protesters and police have become increasingly violent. Police have been criticized for excessive use of force and failing to protect protesters from attacks by what opposition politicians suspected to be criminal gangs.

In a warning to protesters, China’s People’s Liberation Army in Hong Kong on Wednesday released a video of “anti-riot” exercises and its top brass warned violence was “absolutely impermissible.”

The PLA has remained in barracks since the protests started in April, leaving Hong Kong’s police force to deal with them.

Police said seven men and a woman, aged between 24 and 31, were arrested on Friday after a raid on a building in the New Territories district of Sha Tin, where police seized weapons and suspected petrol bombs. Making or possessing explosives illegally can carry a sentence of up to 14 years in jail.

The police may arrest more people as the investigations unfold, police officer Li Kwai Wah said, adding, “Recently we are very worried about the escalating violence.”

Andy Chan, a founder of the pro-independence Hong Kong National Party that was banned last September, was among those arrested. His arrest prompted about 100 protesters to surround a police station to demand his release, television footage showed.

On Wednesday, 44 people were charged in a Hong Kong court with rioting over a recent protest near Beijing’s main representative office in the heart of the city.

The escalating protests, which have shut government offices, blocked roads and disrupted business, is taking a toll on the city’s economy and scaring off tourists.