Carson City, Nev. • A gunman wielding an AK-47 opened fire on a table of uniformed National Guard members at an IHOP restaurant on Tuesday in an outburst of violence that killed four people, wounded eight others and put Nevada’s capital city on high alert.

Five Nevada National Guard troops sitting together at the back of the restaurant were shot — two of them fatally. Another woman was also killed, and the gunman, 32-year-old Eduardo Sencion of Carson City, shot himself in the head and died at a hospital.

The shooter’s motive was unclear, but family members said he had mental issues. He had never been in the military and had no known affiliation with anyone inside the restaurant.

Witnesses and authorities described a frantic scene in the bustling business district, in which the shooter pulled into the large complex of retail stores and shops just before 9 a.m. in a blue minivan with a yellow "Support Our Troops" sticker on the back. He got out and immediately shot a woman near a motorcycle, a witness said.

Ralph Swagler said he grabbed his own weapon, but said it was too late to stop the shooter, who charged into the IHOP through the front doors.

"I wish I had shot at him when he was going in the IHOP," said Swagler, who owns Locals BBQ & Grill. "But when he came at me, when somebody is pointing an automatic weapon at you — you can’t believe the firepower, the kind of rounds coming out of that weapon."

The gunman went all the way to the back of the restaurant to the back area and opened fire, Carson City Sheriff Kenny Furlong said.

When he left the restaurant, he stood in the parking lot and shot into the nearby businesses, shattering the windows of a barbecue restaurant and an H&R Block and a casino across the street.

Officers arrived minutes later and found the suspect and the person who was by the motorcycle wounded and lying in the parking lot. The names of the victims, including two male Guard members who were killed, were not immediately released.

Sencion left two more guns in the van — a rifle and a pistol, authorities said.

As the attack unfolded, Nevada officials worried about the violence being more widespread. They locked down the state Capitol and Supreme Court buildings for about 40 minutes, and put extra security in place at state and military buildings in northern Nevada.

"There were concerns at the onset, so we took certain steps to ensure we had the capability to embrace an even larger circumstance," Furlong said. "At this point in time it appears to be isolated to this parking lot."

Reno-based FBI special agent Michael West said there was no indication of any terrorist plot.

As police interviewed dozens of witnesses after the shooting and kept the gathering crowd of media at bay, a body lay on the ground, covered with a white sheet except for the feet, clad in tan boots.

Sencion was born in Mexico and had a valid U.S. passport. In interviews with investigators after the shooting, his family raised concerns about his mental health, Furlong said. Sencion worked at his family’s business in South Lake Tahoe and had no criminal history. The minivan he drove to the shooting was registered to his brother.

The shooting shocked some who knew him, including Joe Laub, his lawyer in a bankruptcy filing in January 2009, who called it an "aberration of his character."