The stand-off in the Yuen Long district, in which there were no immediate clashes or scuffles, followed violence on Sunday when tens of thousands marched through the Kowloon district and hardcore activists threw petrol bombs at police, torched entrances to metro stations and trashed hundreds of shops.

Under a policy that deems marches illegal unless they have a police permit, police were blocking the way to around 100 protesters trying to reach the Yuen Long metro station in Hong Kong’s northwest, and closed the station five hours early.

Protesters are angry that police did not act quickly enough to protect pro-democracy activists and commuters from the July 21 gang assault on them in the Hong Kong metro, and at what they say is a slow investigation into the incident.

Police have arrested 34 people and charged six.

At the time some believed the men had been hired to attack the group. Some politicians and activists have linked Hong Kong’s shadowy network of triad criminal gangs to political intimidation and violence in recent years, sometimes against pro-democracy activists and critics of Beijing.

Riot police marched down the street ordering protesters to disperse on Monday, warning they would fire tear gas. At one stage they rushed protesters and detained one person.

At one stage scuffles broke out between pro-Beijing supporters and protesters.

“INDEPENDENT INVESTIGATION, JUSTICE”

Yim, a 42-year-old social worker, said he was in Yuen Long station on the night of the attack, adding it was important to continue to protest against such mob violence.

“If they really wanted to catch those attackers they could,” he said. “There were many people filmed that night but they’ve only arrested six people so far ... we want an independent investigation and justice for this attack. The police are selectively enforcing the law.”

Hong Kong has been battered by more than 5 months of anti-government protests, and despite two weeks of calm, Sunday’s mass rally showed there was no end in sight to the unrest.

Embattled Hong Kong chief executive Carrie Lam has rejected the demands of protesters and backed police using violence against them. Many say police have used excessive force against them, firing thousands of rounds of tear gas and hundreds of rubber bullets against brick- and petrol bomb-throwing activists.

Since the protests escalated in June, more than 2,600 people have been arrested, many under 18 years of age, while two people have been shot and many more injured.

Many people in Hong Kong are angry at what they see as mainland China’s attempts to limit the freedoms the city enjoys under the “one country, two systems” principle enshrined in its handover from Britain in 1997.

The protests pose the biggest popular challenge to Chinese President Xi Jinping since he took power. Beijing has denied eroding Hong Kong’s freedoms and Xi has vowed to crush any attempt to split China.

Protesters are demanding universal suffrage, an independent inquiry into alleged police brutality, amnesty for those charged, an end to labeling protesters as rioters, and the formal withdrawal of a China extradition bill which ignited the unrest.