HONG KONG – Thousands of jeering Hong Kong residents held a raucous anti-government protest on Wednesday at a suburban subway station that was attacked by a mob last month, angry that nobody has yet been prosecuted for the violence.

Some masked protesters clashed with police in the sub-tropical heat, spraying fire extinguishers from the inside of Yuen Long station as others smeared the floor with cooking oil to stop the police advancing.

Some demonstrators blocked station exits and sealed roads outside the station, aiming green laser beams at the lines of shield-bearing officers. Others threw empty fire extinguishers at police lines from overpasses.

It was the latest in a series of demonstrations, which have sometimes turned violent, since June against a perceived erosion of freedoms in the Chinese-ruled former British colony.

Wednesday’s protest marked the night of July 21, when more than 100 white-shirted men stormed the Yuen Long station hours after protesters had marched through central Hong Kong and defaced China’s Liaison Office – the main symbol of Beijing’s authority.

Using pipes and clubs, the men attacked black-clad protesters returning from Hong Kong island as well as passers-by, journalists and a lawmaker, wounding 45 people.

Democratic Party legislator Lam Cheuk-ting, who was wounded in the attack by suspected triad gangsters, said he believed the protesters wanted a peaceful night on Wednesday but he could not rule out further violence – from gangsters or the police.

“It is impossible to predict… It is deeply disappointing that all these weeks later we still don’t have an independent inquiry into those events,” he told Reuters.

Squads of police were stationed on the station perimeter and some protesters jeered and shone lasers at them. A small crowd of masked young men gathered on a station balcony, swearing and cursing at police vans down a side street.

Anger erupted in June over a now-suspended bill that would allow criminal suspects in Hong Kong to be extradited to mainland China for trial. Hong Kong leader Carrie Lam said again on Tuesday the legislation was dead.

The unrest has been fueled by broader worries about the erosion of freedoms guaranteed under the “one country, two systems” formula adopted after Hong Kong’s return to China in 1997, including an independent judiciary and the right to protest. Demonstrations have included the storming of the legislature and havoc at the airport.

At a speakers’ corner beneath the MTR station on Wednesday, people denounced police violence and their perceived desertion of duty on July 21.

“They just walked away,” one woman said. “What kind of police are these?”

Peter, a 17-year-old student handing out free drinks and masks, said he wanted the night to be peaceful.

“We need to give the frontline fighters a rest from fighting the police, so they can fight again later if we need,” he said.

The protests have prompted sharp reactions from Beijing, which has accused foreign countries, including the United States, of fomenting unrest. China has also sent clear warning that forceful intervention is possible, with paramilitary forces holding drills in neighboring Shenzhen.

US Secretary of State Mike Pompeo reiterated Washington’s calls for China to honor its commitment to “one country, two systems.”

Speaking to CBS program “This Morning” on Tuesday, Pompeo highlighted remarks by President Donald Trump at the weekend warning against a crackdown like Beijing’s suppression of pro-democracy protests in Tiananmen Square in 1989.

Trump said this would make reaching a deal he has been seeking to end a trade war with China “very hard.”

In an editorial on Tuesday, China’s influential state-run tabloid, the Global Times, called Monday’s comments by US Vice President Mike Pence linking the trade talks to the Hong Kong protests “outrageous.”

Likely worsening already strained ties between Beijing and London, a Chinese national working at Britain’s Hong Kong consulate has been detained in China’s border city of Shenzhen for violating the law.

Some Hong Kong companies have been dragged into controversy amid the protests.

Pilots and cabin crew at Cathay Pacific Airways described a “white terror” of political denunciations, sackings and phone searches by Chinese aviation officials.

The Hong Kong Pharmacists’ Union said it was concerned about the spread of toxic chemicals from the tear gas used by police in some of the protests.

“We would suggest the protective measures and decontamination actions to be taken after the release of tear gas in your community and the mass transit system,” it said in a statement.

Police responded by reading out from Wikipedia that tear gas does not harm humans.