HONG KONG - Hundreds of protesters gathered at the government headquarters in Admiralty on Tuesday night (June 11), as the city geared up for a second wave of protests against a proposed extradition law.

Unfazed by the rain, people with multi-coloured umbrellas started streaming to the complex from about 8pm. By 9pm, the walkway in front of the Legislative Council (LegCo) and the bridge next to it were lined with protesters.

Following Sunday's mass protest - the biggest the city has had since the handover in 1997 - there have been calls from activists online for Hong Kong residents to join a second protest on Tuesday - a sit-in to begin at 10pm.

Student Clara Lam, 22, said she attended the mass rally on Sunday and turned up again on Tuesday because she was upset that Hong Kong Chief Executive Carrie Lam ignored public opposition to the extradition Bill that many in Hong Kong view as an attempt by Beijing to curb the territory's independence.

"Even if we can't achieve anything, let's take it as the last chance for us to do something about this," she said.

Some 5,000 police officers were deployed in anticipation of Tuesday's protest, a local report said. The sit-in comes ahead of a larger rally being planned for Wednesday - the day the extradition Bill is due to be debated by lawmakers.

Unions, teachers, students, non-governmental organisations, churches and the Confederation of Trade Unions, among others, have called for a strike.

Already, some 100 small businesses have pledged to close on Wednesday. More than 40 social welfare and religious groups have also urged employers to let their staff take leave and join the planned rally outside the LegCo.

In an online petition on Tuesday, hundreds of aviation workers urged airline employee unions to call for a formal strike and they demanded the government immediately withdraw its "evil amendments".

Labour Party legislator Fernando Cheung, a co-organiser of the protest planned for Wednesday, had told local media that he expected 2,000 social workers to take part, adding that the groups would ensure there will be emergency services for the needy.

Related Story Business confidence shaken in Hong Kong as government moves to pass extradition Bill

Related Story Hong Kong leader Carrie Lam vows to push ahead with extradition Bill as city gears up for fresh protests, strikes

Related Story Hong Kong businesses pledge closures as extradition anger builds

Student unions at seven major higher education institutions have indicated they would join the protest.

Separately, pro-democracy lawmakers and activists urged people to join them in surrounding the LegCo complex from Wednesday until next Thursday, when the Bill is expected to be voted on.

In anticipation of the protests, officials cordoned off the demonstration area and Civic Square on Tuesday, and deployed officers to patrol the area. The police also warned that they will take action against those who breach the law.

The stern warning follows Sunday night's storming of the LegCo by some 350 protesters. They had stayed behind after the rally ended at 10pm and clashed with the police.

Eight officers and unknown number of protesters were injured, while at least 19 people were arrested.

Meanwhile, Singapore's Consulate-General in Hong Kong on Tuesday advised Singaporeans to avoid travelling to Admiralty and Wanchai, areas with large crowds and mass gatherings expected in the coming days.