WASHINGTON: The gunman who killed six people inside a Sikh temple in the US and was killed in a police shootout was a 40-year-old Army veteran, officials said Monday, and a civil rights group identified him as a “frustrated neo-Nazi” who led a white supremacist band.

Police called Sunday’s attack an act of domestic terrorism.

The shooter was Wade Michael Page, said First Assistant US Attorney Greg Haanstad in Milwaukee. Page joined the Army in 1992 and was discharged in 1998, according to a US defense official who spoke on condition of anonymity because he was not authorized to release information about the suspect.

Officials and witnesses said the gunman walked into the Sikh Temple of Wisconsin and opened fire as several dozen people prepared for Sunday morning services. Six were killed, and three were critically wounded.

Page was a “frustrated neo-Nazi” who led a racist white supremacist band, the Southern Poverty Law Center said Monday. Page told a white supremacist website in an interview in 2010 that he had been part of the white power music scene since 2000, when he left his native Colorado and started the band, End Apathy, in 2005, the civil rights organization said.

He told the website his “inspiration was based on frustration that we have the potential to accomplish so much more as individuals and a society in whole,” according to the SPLC. He did not mention violence in the interview.

Page joined the military in 1992 and was a repairman for the Hawk missile system before switching jobs to become one of the Army’s psychological operations specialists, according to the defense official.

So-called “Psy-Ops” specialists are responsible for the analysis, development and distribution of intelligence used for information and psychological effect; they research and analyze methods of influencing foreign populations.

Fort Bragg, North Carolina, was among bases where Page served.        Joseph Rackley of North Carolina told The Associated Press that Page lived with his son for about six months last year in a house on Rackley’s property.

Wade was bald and had tattoos all over his arms, Rackley said, but he doesn’t remember what they depicted. He said he wasn’t aware of any ties Page may have had to white supremacists.

“I’m not a nosy kind of guy,” Rackley said. “When he stayed with my son, I don’t even know if Wade played music. But my son plays alternative music, and periodically I’d have to call them because I could hear more than I wanted to hear.”