Police fired tear gas at protesters in Hong Kong on Sunday for the second night in a row in another escalation of pro-democracy demonstrations.

Protesters occupied two areas at opposite ends of central Hong Kong following a mid-afternoon rally against police use of tear gas the previous Sunday.

As night fell, one group that had blocked a road near the Chinese government’s liaison office began to move forward. The police issued warnings, and protesters were seen throwing eggs at them. Officers fired tear gas to halt the advance.

Protesters had earlier rallied at a park in Hong Kong’s financial district before marching out in several directions despite not getting police approval for a public procession. It was the second straight day that protesters had taken to the streets without official permission.

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A sea of black-shirted protesters, some with bright yellow helmets and masks but many with just backpacks, streamed out of Chater Garden park.

Chanting “Add oil”, a phrase that roughly translates as “Keep up the fight”, a huge crowd marched east down a wide thoroughfare in what has become a summer of protest in the semi-autonomous Chinese territory.

They stopped near the Sogo department store and set up barricades to block off the area and defend it against police.

Another group headed west toward mainland China’s liaison office.

Protesters egged the office last weekend and splattered black ink on the national emblem, eliciting an angry reaction from the Chinese government.

They stopped about two blocks short of the office and used orange and white construction barricades to build a wall spanning a major road.

They massed behind the barriers as night fell, with umbrellas pointed forward to shield their identities and ward off any police move to clear them.

Some nearby stores closed early as police in riot gear gathered nearby ahead of the all but inevitable clearing operation.

Hong Kong has been wracked by protests for seven weeks, as opposition to an extradition bill has morphed into demands for the resignation of the city’s leader, Carrie Lam, and an investigation into whether police have used excessive force in quelling the protests.

Underlying the movement is a broader push for full democracy in the territory. The city’s leader is chosen by a committee dominated by a pro-Beijing establishment, rather than by direct elections.

The rally in Chater Garden was called to protest over the police use of tear gas, rubber bullets and other force to break up a demonstration the previous Sunday.

“We need to have a protest to show that we are strongly against this kind of brutality and we need them to respond to our demands,” said rally organiser Ventus Lau.

Police had refused Lau’s request to march west to the Sheung Wan district, where the tear gas was used the previous weekend, citing escalating violence in clashes with protesters that have broken out after past marches and rallies.

“The police must prevent aggressive protesters from exploiting a peaceful procession to cause troubles and violent clashes,” said Superintendent Louis Lau, of the police public relations branch.

On Saturday, clashes between protesters and police led to 11 arrests and left at least two dozen injured in an outlying district toward the border with mainland China.

The police had also denied permission for that march in Yuen Long, where a mob apparently targeting demonstrators had beaten people brutally in a railway station the previous weekend.

Protesters and police faced off in the streets well into the night, as they have done repeatedly during the summer’s pro-democracy protests.

Police said protesters removed fences from roads to make their own roadblocks and charged police lines with metal poles. One group surrounded and vandalised a police vehicle, causing danger to officers on board, a police statement said.

Officers fired tear gas and rubber bullets as demonstrators threw bricks and other objects and ducked behind makeshift shields.

Later, police wearing helmets charged into the railway station, where a few hundred protesters had taken refuge from the tear gas.

Some officers swung their batons at demonstrators, while others appeared to be urging their colleagues to hang back.

For the second week in a row, blood was spattered on the station floor.