San Francisco's Chinese community has expressed support for African Americans following the police killing of George Floyd.

"Words cannot express adequately the sense of dismay, regret, and grief caused by the death of George Floyd and others as we all cope with the long legacy of failures by government and the US criminal justice system to address the scourge of racial inequity, bigotry, and violence in this society," said Doug Chan, president of the Chinese Historical Society of America.

"The killing of Floyd informs us that we all must do more as a community to address, through a process of political, economic, and social reform, the racial and ethnic prejudices that can destroy our society literally within a heartbeat," he said.

Demonstrations have continued for nearly two weeks across the US, following the death of Floyd, a 46-year-old black man who died after Derek Chauvin, a white policeman, knelt on his neck for nearly nine minutes on May 25 in Minneapolis, Minnesota.

Also, members of the Chinese Progressive Association joined thousands of others at a kneeling protest on Monday in front of San Francisco City Hall to demand justice for all black families brutalized by police.

San Francisco also has had to cope with instance of looting amid the unrest.

Businesses in San Francisco sustained widespread damage on May 30 after what started as peaceful protests turned into an outbreak of looting that reached Chinatown around 11:30 pm, recalled Leanna Louie, a member of a neighborhood watch group United Peace Corps.

Louie witnessed a group of about 50 looters ransacking stores on Grant Avenue, mostly jewelry stores, in Chinatown, when she and two other members were patrolling the neighborhood in their car.

"It was horrifying. I've never seen that in my life," said Louie, an Army veteran. Her group has been patrolling Chinatown for nine weeks due to the rising wave of anti-Chinese racism during the COVID-19 pandemic.

Afraid of more looting and vandalism, many stores have closed or reduced hours, and some have even put up "for rent" signs. Since June 2 night, there have been more police stationed in Chinatown, said Louie.

The mass protests also led to curfews in at least 140 cities in the country.

The "terrible and sad incidents of apparent looting and burglary "were rare in San Francisco Chinatown's modern history", said Chan.

The first recorded and significant instance of rioting, looting, and property destruction in and against San Francisco's Chinatown occurred in 1877, and the racist violence caused four deaths and the destruction of more than $100,000 worth of property belonging to the city's Chinese immigrant population, said Chan.

"In an eerie parallel to our times, the local police department had been overwhelmed, and the rioting only stopped because of the combined efforts of police, the state militia, and as many as 1,000 members of citizen's vigilance committee," he said.

Another instance of looting in Chinatown happened during the 1906 San Francisco earthquake. "We know about the extent of such looting from dispatches by the National Guard commander to his superiors," said Chan. "A sample of such a dispatch recites that even 15 to 20 National Guard troopers had been arrested for looting 'principally in Chinatown' after the Great Earthquake and Fire."

The last curfew set in the city was in response to the 1979 White Night riots, which didn't reach Chinatown. "The issues and the adversaries (of the 1979 riots) were narrower than what we are witnessing today," said Chan.

Asians 4 Black Lives, a group from the Bay Area, denounced the "gross displays of state-sanctioned police violence", saying in a statement that police violence is not the result of some officers being "a few bad apples", but that "the trees producing these apples are rotten to the roots".