"Unfortunately, I did not take the time to proofread what was recorded. I absolutely did not say that," Stewart told the Riverside Press-Enterprise on Thursday.

"What I said is and I don't believe there has ever been a person of colour murdered by police, on context to Temecula or Riverside County. I absolutely did not say 'good.' I have no idea how that popped up."

Stewart said he was replying to someone "concerned about our police officers and their sensitivity training".

The city issued a press release late on Thursday announcing that Stewart, who was elected to a four-year term in 2016, was stepping down from his post and the city council, news outlets reported.

"You have every right to be hurt and offended. My typos and off-the-cuff response to an email on a serious topic added pain at a time where our community, and our country, is suffering," Stewart said in a statement. "I may not be the best writer and I sometimes misspeak, but I am not racist."

He said he was resigning because he understood his "sincerest apologies cannot remedy this situation".

The initial email came as cities around California were the scenes of large demonstrations over the death of George Floyd, a black man who died last week after a white Minneapolis police officer pressed a knee on his neck. Four police officers have been charged in his death.

Stewart's email message also said that "racism is not excepted or tolerated" in the city or surrounding areas.

"I have several good friends who are African Americans, and they love living here because how safe it is for them and their families," the email said.

AP