SAN FRANCISCO >> San Francisco officials decided today to force some people with serious mental illness and drug addiction into treatment, even if it goes against the spirit of a city known for its fierce protection of civil rights.

Several members of the Board of Supervisors voiced deep concerns today about the possibility of taking away a person’s civil liberties, but the proposal for a pilot program passed 10-1.

Mayor London Breed and other supporters say the move — known as conservatorship — is necessary to help people who are often homeless, addicted to drugs and have a mental illness, making them a danger to themselves.

“Allowing people to continue to suffer on our streets is not acceptable or humane, and I am glad the Board of Supervisors supported our approach to finally make a change,” Breed said in a statement after the vote.

The measure would apply to a handful of people, the city’s department of public health estimated, although the number would grow under legislation pending at the state level.

Supervisor Shamann Walton was the sole no vote, saying the city didn’t have plans in place to reduce the impact on African American people and other minorities who tend to have negative run-ins with police.

Several supervisors decided to give the pilot program a try after changes were made that require providers to give the person multiple opportunities to accept voluntary help. They also were encouraged by Breed including more money for additional treatment beds in a proposed budget.

“By all accounts, the number of people affected will be small, but no matter how small the number, we all need to be watching closely to make sure the impacts are positive,” said Supervisor Vallie Brown, a co-sponsor of the proposal.

Critics call the measure politically driven and a violation of civil rights that runs against the principles of the liberal city. They say it would lead to locking up people in facilities and that San Francisco lacks the resources to successfully expand the number of people in such a program.

“We are concerned about ensuring that persons receive mental health treatment and services in their communities, in supportive housing, in supportive environments — and not in facilities,” said Curt Child, legislative director of Disability Rights California.

“This is a major civil rights issue in the sense of confining people against their will,” he said.

San Francisco struggles with income inequality and a growing number of homeless people — some with disturbing behavior tied to drugs, schizophrenia or bipolar disorder. They shuffle from the streets to jail and psychiatric care, unaware they need steady treatment, sometimes dashing into traffic or screaming at strangers.

Supervisor Rafael Mandelman, another co-sponsor, says business owners and residents in his district see such people go “from ‘kind of not great’ to being in absolute and complete distress.”

Sen. Scott Wiener, a San Francisco Democrat, co-authored state legislation that allows pilot programs in Los Angeles, San Francisco and San Diego counties. He is working on changing that legislation to expand the number of people affected.

“Too many people are deteriorating and dying on San Francisco’s streets, and we have a moral responsibility to help them,” he said in a statement after the vote. “It’s neither progressive nor compassionate to stand by while people die.”

Supervisors in San Diego and Los Angeles counties have not officially considered it. Los Angeles County saw a 12% rise in the number of homeless people over the past year.

San Francisco’s program would allow a court to appoint a public conservator for someone who has been involuntarily detained for psychiatric hospitalization at least eight times in a year. The treatment could last for as long as a year.

Only about five people could be forced into treatment in San Francisco, said Rachael Kagan, spokeswoman for the city’s Department of Public Health. Wiener’s new bill could bump that up to 55, which is the number of people who now fit the definition for at least eight holds.

The health department has identified an additional 48 people who have been detained six or seven times.