A 21-year-old suspect described as a sex addict was charged Wednesday with murdering eight people in spas around the US city of Atlanta, in triple attacks that have deeply shaken the Asian-American community.

Police said Robert Aaron Long has denied a racist motive to Tuesday's attacks -- in which six of the victims were women of Asian origin -- but that they had yet to determine the shooter's reason for opening fire.

"The suspect did take responsibility for the shootings," Captain Jay Baker of the Cherokee County Office told a news conference.

Long, who is white, "does claim it was not racially motivated," Baker added, but stressed that it was "still early" in the investigation.

The suspect "apparently has an issue, what he considers a sex addiction," Baker said.

Long told police he had frequented massage parlors in the past and launched the attacks as a form of vengeance against "a temptation for him that he wanted to eliminate."

While a probe is ongoing into the motive, the attacks thrust the spotlight onto a spike in violence targeting Asian-Americans -- fueled during the Covid-19 pandemic, activists believe, by talk of the "Chinese virus" by former president Donald Trump and others.

"Racially motivated violence must be called out for exactly what it is," Congresswoman Marilyn Strickland -- who is half-Korean -- said Wednesday.

"We must stop making excuses or rebranding it as economic anxiety or sexual addiction."

The spotlight has also been thrust on the police leading the investigation -- particularly on Captain Baker's remarks that the alleged shooter had had a "bad day".

Scrutiny has also focused on a post purported to be from Baker's private Facebook account and shared by Buzzfeed showing him promoting T-shirts describing Covid-19 as an "imported virus" from China.

"We have lost so many lives this past year. We have seen racism and discrimination and a surge of violence against Asian-Americans who are scapegoated because of the pandemic," Sam Park, a local representative of the Asian-American community, told AFP in Atlanta.

"It shocks the conscience," he said of the attacks.

President Joe Biden, who spoke out last week against the spike in anti-Asian violence, once again called it "very troublesome" -- while stressing that motivation in the Atlanta shootings had yet to be determined.

Eight counts of murder 

Tuesday's rampage began with an attack at Young's Asian Massage in Acworth, an Atlanta suburb, where four of the victims were killed and a man was wounded.

Police said four women were subsequently killed in attacks on two neighboring spas in the northeast of Atlanta.

In the initial attack, the county sheriff's department has charged Long with four counts of murder and one count of aggravated assault.

He was also charged with four counts of murder relating to the double Atlanta attack, the city's police department announced.

Authorities arrested Long after tracking his phone following a brief pursuit about 150 miles (240 kilometers) from Atlanta, officials said.

After he was detained, "he made a comment... that he was headed to Florida and that he was going to do similar acts in that state," Baker said, adding that Long wanted to target "some type of porn industry."

Violence in the US

Cherokee County Sheriff Frank Reynolds said Acworth, a normally quiet commuter community, had experienced few murders and Tuesday's violence was "a shock to all of us."

"This is the hardest thing I've ever, ever in my whole life, had to deal with," Margaret Rushing, mother of Delaina Ashley Yaun, one of the victims of the shootings, told AFP.

"She was my best friend, my daughter."

South Korea's foreign ministry has said four of the victims were of Korean descent, according to Seoul's Yonhap news agency.

Pentagon chief Lloyd Austin, speaking during an official visit to Seoul, said: "our deepest sympathies go out to all those affected by this horrific crime and especially the families of those who were killed."

The state of Georgia, of which Atlanta is the capital, is home to nearly 500,000 people of Asian origin, or just over four percent of its population, according to the Asian American Advocacy Fund.

The shootings came the same day as the release of a report by the advocacy group Stop AAPI Hate, which suggested a marked increase in hate crimes against Asian-Americans -- with women disproportionately affected. 

In a tally of incidents reported to the group between March 2020 and February this year, almost 70 percent of Asian-American survey respondents said they had faced verbal harassment and just over one in 10 said they had experienced physical assault.