FILE - This Feb. 3, 2016 file photo San Francisco Police Chief Greg Suhr speaks during a news conference in San Francisco. Additional San Francisco police officers have been accused of exchanging racist and homophobic text messages, following a scandal that implicated 14 officers in a department now under federal review. Photo: AP Photo/David J. Phillip,File

FILE - This Feb. 3, 2016 file photo San Francisco Police Chief Greg Suhr speaks during a news conference in San Francisco. Additional San Francisco police officers have been accused of exchanging racist and homophobic text messages, following a scandal that implicated 14 officers in a department now under federal review. Photo: AP Photo/David J. Phillip,File

SAN FRANCISCO — Additional San Francisco police officers have been accused of exchanging racist and homophobic text messages, following a scandal that implicated 14 officers in a department now under federal review, authorities said.

The new allegations in the liberal and diverse city come amid a national debate over police relations with minority communities. The city’s police chief, mayor and others asked the U.S. Justice Department this year to review the agency’s use of force and ethnic disparities in arrests amid rising racial tensions.

Four officers exchanged messages that included racist remarks and derogatory comments toward the gay community, Police Chief Greg Suhr said Thursday. He says the officers face termination or already have left the force.

The officers sent the texts on their personal cellphones between 2014 and late 2015, District Attorney George Gascon said. It was not clear if they were on duty at the time.

The allegations emerged during a recent sexual assault investigation against an officer. Investigators searched cellphone records of the officers, who had sent text messages containing “reprehensible racial and homophobic remarks,” the Police Department said in a statement.

The investigation also revealed that three other officers had each received a single questionable text message from the officer accused of sexual assault, but did not respond. There was not enough evidence to bring charges against them, investigators concluded.

The officer at the center of the investigation has been charged with six misdemeanor counts of misusing police databases, and Suhr says he will launch termination proceedings after the criminal case wraps up.

The police chief said anyone exchanging racist or homophobic text messages “clearly falls below the minimum standard for being a San Francisco police officer.”