“Once again we see that hate is deadly,” Senator Raphael Warnock of Georgia said on Twitter.

An official from the South Korean Consulate in Atlanta, citing the Foreign Ministry in Seoul, confirmed on Wednesday that four of the eight killed were ethnic Koreans. But the nationalities of the four women were not immediately known, the official said.

Atlanta officials did not ask other massage parlors in the area to shut down as a precautionary measure, the police chief, Rodney Bryant, said at a news conference. But fear was palpable among some who work in the massage industry. A woman who answered the phone at Healing Massage Spa and identified herself as a manager said that after the shootings were reported on the news, her boss told her to close for the night.

About a 30-minute drive northwest of the Atlanta spas, Young’s Asian Massage is tucked in a modest strip mall, with a beauty salon on one side and a boutique on the other. Like much of suburban Georgia, it is a diverse place, with panaderias and Latin businesses and American-style chain restaurants.

On Tuesday night, the blue lights of police vehicles cast an eerie glow as detectives worked inside the spa.

Rita Barron, 47, the owner of Gabby’s Boutique next door, was with a group of onlookers standing near a used car lot. She said she had been with a customer when she heard noises through the wall that sounded like claps — and then women screaming.

She called 911, and soon saw victims being taken out by police officers.

Nearby, a wail of anguish went up from another cluster of people waiting for any news. Three dropped to the pavement, two of them embracing and shaking as they cried.

Richard Fausset reported from Acworth, Ga., and Neil Vigdor from Greenwich, Conn. Reporting was contributed by Sean Keenan from Atlanta; Azi Paybarah from Albany, N.Y.; Giulia McDonnell Nieto del Rio from New York; and Choe Sang-Hun from Seoul.