SIGNAL HILL — A disgruntled employee shot and seriously wounded three co-workers at a menu printing plant Monday, then killed himself before a SWAT team entered the building, authorities said.

The man, about 67, entered Kenyon Press shortly after 9 a.m., walked past a superior and opened fire on the victims with a semiautomatic handgun, said police Capt. Mary Risinger.

The business owner told police that the man, whose name was withheld, had indicated he was upset about a reduction in work for all employees, Risinger said. The owner wasn’t present during the shooting.

The cutback began six months ago and for the last 1 1/2 months the man had not had any hours, Risinger said.

All anyone heard him say was “shut up” to someone before he shot the three men, who apparently had helped him get the job assembling menus about a year ago, Risinger said. The man wasn’t scheduled to work Monday.

Victims Rafael Mendoza, 46, shot once in the back and once in the left elbow, and Sergio Garcia, 49, shot once in the chest and once in the left shoulder, were in fair but stable condition at Long Beach Memorial Medical Center, said trauma surgeon Gergis Ghobrial. Part of Mendoza’s spine was also fractured.

“They were very shocked,” Ghobrial said. “They could not talk but now they seem to be more relaxed.”

There was no immediate information on the other victim, who was taken to St. Mary Medical Center.

A dozen workers were in the business at the time of the attack. A female worker locked herself in a room and called 911 when the shooting started.

By the time police arrived some employees, including two of the wounded, had evacuated. Officers got the other employees and the remaining wounded man out of the building.

Ray Luna, 34, saw the chaos from a construction business where he works across the street.

“A lot of the employees looked like they were scared,” said Luna. “Some of them were running from the back of the building. The other ones were coming out from the front door. And the cops were pulling them out with guns drawn and frisking them down.”

One of the wounded had a torso injury and another had an arm injury, said Luna, whose own workplace was evacuated.

“It was pretty scary. At any point we were ready to hit the deck,” he said.

The total number of shots fired wasn’t known, Risinger said.

The SWAT operation was conducted by a team from neighboring Long Beach.

Kenyon Press, which makes custom designed menus, has customer service personnel, copywriters, designers, illustrators, proofreaders, prepress, press and bindery/manufacturing workers.

Its clientele includes Las Vegas casinos and hotel chains, according to its Web site.

Signal Hill, a city of about 11,000, is 20 miles south of Los Angeles, surrounded by Long Beach.