Federal agents on Wednesday joined the investigations into shootings at three Atlanta-area spas that left eight people dead Tuesday evening.
The attacks began around 5 p.m., when four people were killed in Acworth, a suburb north of Atlanta, authorities said. Less than an hour later, four women were killed in two shootings in Atlanta. The victims in Atlanta appeared to be Asian women, as were two of the victims in Acworth, officials said.
Authorities arrested a suspect, Robert Aaron Long, 21, of Woodstock, after a brief manhunt, Cherokee County sheriff's Capt. Jay Baker said. Investigators were working to confirm that the shootings were related.
The FBI was "assisting the local investigations," the agency said early Wednesday. No other details were released about FBI's involvement.
The Atlanta Police Department scheduled a 10:30 a.m. press conference to discuss the case.
Atlanta Mayor Keisha Lance Bottoms said in a statement that "a crime against any community is a crime against us all."
"I commend law enforcement for their quick work in arresting a suspect in the tragic shootings," she said. "I have remained in close contact with the White House and APD as they work with federal, state and local partners to investigate the suspect who is responsible for this senseless violence in our city."
White House press secretary Jen Psaki said Wednesday that President Joe Biden had been briefed "overnight about the horrific shootings in Atlanta."
"White House officials have been in touch with the mayor’s office and will remain in touch with the FBI," Psaki said.
South Korea’s foreign ministry told NBC News that four of the women who died were of Korean origin, but their nationalities have yet to be verified.
Authorities did not provide additional details or identifying information about the other victims. Nor did they disclose a suspected motive.
"We are in the very early stages of this," Atlanta Police Chief Rodney Bryant said.
Baker said Cherokee County deputies discovered two people dead and three others wounded at the massage parlor in Acworth. The injured were taken to a hospital, where two of them died, he said.
About 45 minutes later and 30 miles away, police in Atlanta responded to a report of a robbery on Piedmont Road in the northeast part of the city.
Officials discovered three women dead from apparent gunshot wounds, and while on the scene, received a call of shots fired across the street, where a woman was found dead inside that business, Atlanta police said.
Chief Bryant described one location as a spa, and another as an aromatherapy spa.
After the Acworth shooting, the sheriff's office released photos of a suspect.
Long was arrested in Crisp County, about 125 miles south of Atlanta, officials said.
His vehicle was spotted southbound on I-75, and a Georgia State Patrol trooper used a PIT maneuver, in which a police car is used to physically stop another vehicle, the Crisp County Sheriff's Office said.
The killings come amid a growing number of anti-Asian hate incidents. Research released through Stop AAPI Hate on Tuesday revealed that nearly 3,800 incidents were reported over the course of roughly a year during the pandemic and that a disproportionate number of attacks were directed at women.
During a visit to South Korea this week, Secretary of State Antony Blinken addressed the shootings, and said that this type of violence had no place in America or anywhere.
"We will stand up for the right of our fellow Americans and Korean Americans to be safe and to be treated with dignity," he said.
Because the shootings were all at massage parlors and spas, Atlanta police said officers were dispatched to similar businesses, and that patrols were increased.
In New York City, police were deploying counterterrorism officers to Asian communities out of an abundance of caution, a department spokesperson said.
Seattle Mayor Jenny Durkan called the violence in Atlanta "an act of hate" and said that she and Police Chief Adrian Diaz were taking additional steps to protect Asian American communities in Seattle, including additional police patrols.
After the slayings, Sen. Raphael Warnock, D-Ga., said he was praying for the victims' families and community. "My heart is broken tonight after the tragic violence in Atlanta that took eight lives. Once again we see that hate is deadly. Praying for the families of the victims and for peace for the community," he tweeted.
"Our entire family is praying for the victims of these horrific acts of violence," Georgia Gov. Brian Kemp tweeted, adding his appreciation for the quick apprehension of a suspect by law enforcement.
Baker, the Cherokee County captain, said deadly violence was rare for the area.
"This is not very common for us," he said. "In 2020, we had one homicide."
This article was originally published on NBCNews.com.