SAN FRANCISCO — Police Chief Gregory P. Suhr on Friday announced that all officers on the San Francisco force would be required to complete anti-bias training as he released nine pages of racist text messages between three officers that further tarnished the image of a department under federal investigation.

“We have nothing to hide,” said Chief Suhr. “These are the actions of a few.”

But the city’s public defender and experts on criminal justice said the texts appeared to reveal a deep culture of bias in the 2,000-member force that contradicts the city’s image of tolerance and liberalism.

“These texts evidence a deep culture of racial hatred and animus against blacks, Latinos, gays and even South Asians,” Jeff Adachi, the public defender, said in an interview. “It can no longer be said to be an isolated problem.”

A number of police departments, including those in Miami and Los Angeles, have had problems with racist messages sent by their officers. Experts in criminal justice have debated how to address bias, both conscious and unconscious.