The complaint was sent to East Palo Alto officials after police Chief Ron Davis announced last month that he was leaving for a federal job in Washington, D.C., according to the Palo Alto Daily News.
Davis left his post in this city of about 28,000 about 30 miles south of San Francisco to become director of the U.S. Justice Department's Office of Community Policing. A phone message and email to the office seeking comment weren't immediately returned. The office's website says he was sworn in on Nov. 12.
In the Nov. 1 complaint, the four officers accuse Davis of creating a hostile work environment for black employees and showing bias in hiring, promotions and assignments.
"His temperament toward African-American employees is abrasive, belittling and dismissive," according to the three-page complaint by Sgts. Roderick Norris and Renaldo Rhodes and Officers Paul Norris and Paul Hines.
Assistant City Manager Barbara Powell told the Daily News that she couldn't talk about the complaint because it's a confidential personnel matter.
"The city takes this very seriously, and the city will be following up on it," Powell said.
The newspaper said Davis could not be reached for comment.
A police department dispatcher told The Associated Press that neither its new police chief nor other administrative staff members were on duty Saturday. A phone message seeking comment was not immediately returned.
The three-page letter to Powell cites several examples of Davis' actions or behaviors that the officers allege support their claims of racial discrimination.
The complaint says African-American senior officers are routinely passed over for sergeant positions, there are no black detectives in the investigative division, and only one black police officer was hired from mid-2005 to mid-2013.
"The examples that have been cited are a minute glimpse into the ongoing suffering endured by African American employees since Chief Davis took over the department," the complaint states.
During his 8½-year tenure in East Palo Alto, Davis was credited for implementing progressive anti-crime initiatives and reducing the city's high murder rate.