Eun-Sook Lee, director of the National Korean American Service and Education Consortium, a Los Angeles-based civil rights organization, said media reports focusing on the gunman's nationality made it seem more than an isolated incident.

"On the radio, I don't hear them saying he was a college student or just a disturbed kid," said Lee. "They say he's a South Korean national."

Authorities on Tuesday identified the shooter as Cho Seung-Hui, a 23-year-old senior majoring in English. He arrived in the United States as boy from South Korea in 1992 and was raised in suburban Washington, D.C., officials said.

Lee said her organization had received a half-dozen angry calls Tuesday, but no threats.

"We are getting calls from people yelling at us because we are Korean," said Lee.

To combat any misrepresentation of Korean immigrants, and to show support for the families of the victims, Korean groups are trying to make sure many Koreans attend vigils and memorials for the killed students, said Lee.

No vigils or demonstrations were planned in Los Angeles' vast Koreatown so far, but may happen in the next couple days, said Lee.

Nearly 200,000 Koreans live in Los Angeles, according to the U.S. Census, by far the largest grouping of America's estimated 1.2 million Korean immigrants.

The shooting and the fact the gunman was from South Korea, was on the front page of Korean online newspapers Tuesday and the subject of Korean language radio talk and television shows.

Still, Koreans see it as an isolated incident that has nothing to do with the Korean community, said Cliff Lee, president of Young Koreans United of USA, a Los Angeles-based advocacy group for Korean-Americans.