Four armed robbery suspects held patrons and employees at an El Monte health spa for four hours before surrendering early Saturday, authorities said.
A total of 22 customers and employees at the R & R Health Club were released about 1:15 a.m., Los Angeles County Sheriff's Deputy George Ducoulombier said.
No injuries were reported in the incident.
Michael Chan, 27; Tommy To, 19, and Si Sin, 19, all of Los Angeles, and Cau Ung, 18, of Rosemead were being held for investigation of robbery, Ducoulombier said.
Authorities said they were tipped off to the robbery about 10 p.m. by a caller who said a friend had contacted him from inside the club.
Officers went to the health club and stopped three male customers in various stages of dress as they fled through a rear door, Ducoulombier said.
Apparently the customers were showering or swimming when the robbery began, the deputy said.
Deputies surrounded the building after the customers told them that the robbery suspects were possibly armed, Ducoulombier said.
Chan later walked out the front door, wearing a business suit and posing as a victim, Ducoulombier said. But authorities searched Chan and found a loaded .45-caliber semiautomatic pistol.
"He said the robbers forced him to carry the weapon," the deputy said. "He told police there were four (men) inside, all armed."
Chan was detained while police waited for the others to leave the building, Ducoulombier said.
About 1 a.m. Saturday, officers saw three men on the roof of the club, and a short time later the customers and club employees left the building.
According to investigators, some of those held said they had been robbed of personal items and money.
About 2:15 a.m., To, Sin, and Ung came down from the roof and surrendered to sheriff's officials. Members of the sheriff's SWAT team found no other suspects or weapons at the scene.
Each of the four suspects is being held on $25,000 bail.