SAN FRANCISCO (AP) — San Francisco police officers are being asked to combat racism in the ranks and take a pledge to turn in colleagues displaying intolerant behavior, such as slurs and jokes targeting people of color, gays and women.

The pledge is part of a broader public relations campaign by the embattled police department to repair frayed relations with minority neighborhoods and community activists.

The campaign comes amid growing tensions between police and black communities that are shaking up departments across the country and have led to the dismissal of top brass in some cities, including Chicago. Politically progressive San Francisco is not immune from the unrest. The Dec. 2 shooting of a young black man clutching a kitchen knife by five officers has increased racial tensions and sparked calls for the police chief's removal.

So far, San Francisco's mayor has stood behind the chief amid the emergence of racist text messages exchanged among several officers and a judge's decision that he failed to punish the officers in timely fashion.

Police say Mario Woods, 26, had stabbed a stranger earlier that day, ignored commands to drop the knife and shook off blasts of tear gas and shots from a bean bag gun before officers opened fire.

Police say only one of the five officers involved was white, but protests over the shooting persists. Mayor Ed Lee has asked the U.S. Department of Justice to investigate.

Chief Greg Suhr said the pledge and the "Not on My Watch" campaign had been in the works long before the Woods shooting, but the incident gave the project new urgency. Several angry protests were organized in the rough neighborhood where Woods died. And people demanding the chief's dismissal disrupted the mayor's inauguration on Jan. 8 and briefly shut down the San Francisco-Oakland Bay Bridge on Martin Luther King Jr. Day on Jan. 18.

Yulanda Williams, who leads a minority police officers group, helped initiate the pledge after she found that a white colleague used a black slur in text messages to other officers complaining about her promotion to sergeant. Other text messages exchanged among Williams' colleagues contained racist and homophobic insults and slurs.

"I will not tolerate hate or bigotry in our community or from my fellow officers," the seven-sentence pledge states in part. "I will confront intolerance and report any such conduct without question or pause."

The department has also launched the website http://notonmywatchsfpd.org/ which instructs citizens and officers on how to file complaints against the police. The website includes a 10-minute video produced by a former television journalist, showing the chief, several officers and civic leaders reciting and discussing the pledge and the importance of rooting out intolerance in the ranks.

Law enforcement experts say San Francisco's pledge is a novel way to try and tamp down rising tensions.

"I think it sends a good signal," said University of South Carolina School of Law professor Seth Soughton, a former police officer and law enforcement scholar. "But whether or not the signal is strong enough remains to be seen."

The Rev. Amos Brown, head of the local NAACP, chapter supports the pledge and called it a "step in the right direction."

The police officers' union has endorsed the pledge, though San Francisco Police Officers Association president Martin Halloran says reciting it is voluntary.

The police chief hopes every officer will recite the voluntary pledge every January to help instill a culture of tolerance and accountability. Police cadets read the pledge Jan. 15 at their graduation.

"I really think it's important that the public hear us say the words," Suhr said.

The pledge is one of several changes Suhr made in the department since the racist text messages emerged from a police corruption case. Suhr has been trying to fire eight officers implicated in the scandal, but a judge recently ruled that he waited too long to discipline them after discovering the texts two years ago. Suhr is appealing.

Suhr reintroduced a proposal to equip officers with stun guns to help deal with confrontations like the Woods shooting and has announced a number of other "use-of-force" policy changes.

Officers must now report whenever they point their guns at suspects. Firearms training has been changed to emphasize other "less-than-lethal" options. And the department is developing ways to deal with knife-wielding suspects.

The pledge is not asking officers to "snitch" on one another, Suhr said. Rather, he said, it is intended to reinforce that the police department reflects the tolerant and diverse culture of San Francisco.

"It's what we swore to do," Suhr said. "People that would use racial epithets, slurs and things like that clearly fall below the minimum standard of being a police officer. A cop needs to show character and point that out."