HONG KONG (AP) — More than 50,000 people rallied in support of the Hong Kong police on Sunday as the semi-autonomous territory braced for another day of protests on the anniversary of the former British colony's return to China.

The crowd filled a park in front of the legislature and chanted "Thank you" to the police, who have been criticized for using tear gas and rubber bullets during clashes with demonstrators that left dozens injured on June 12. Some carried Chinese flags. Police estimated the turnout at 53,000.

A protest march has been called for Monday, the third in three weeks, this one on the 22nd anniversary of the handover of Hong Kong to China on July 1, 1997. Activists have also said they will try to disrupt an annual flag-raising ceremony attended by senior Hong Kong and mainland Chinese officials in the morning.

Police have erected tall barriers and shut off access to Golden Bauhinia Square, where the flag-raising will be held, to prevent protesters from massing there overnight.

The anniversary always draws protests, but this year's is expected to be larger than usual because of widespread opposition to a government proposal to allow suspects to be extradited to mainland China to face charges. More than a million people took to the streets in two previous marches in June, organizers estimate.

The proposal has awakened broader fears that China is eroding the freedoms and rights that Hong Kong is guaranteed for 50 years after the handover under a "one country, two systems" framework.

The government has already postponed debate on the extradition bill indefinitely, leaving it to die, but protest leaders want the legislation formally withdrawn and the resignation of Hong Kong's leader, Chief Executive Carrie Lam. They also are demanding an independent inquiry into police actions on June 12.

Hundreds of people gathered Sunday at the Education University of Hong Kong to hold a moment of silence and lay flowers for a 21-year-old student who fell to her death the previous day in an apparent suicide. Hong Kong media reports said she wrote a message on a wall stating the protesters' demands and asking others to persist.

"It's reminding us we need to keep going on the process of fighting with the, I wouldn't say fighting with the government, but we need to keep going on fighting not to have the extradition law," said student Gabriel Lau.