LOS ANGELES (AP) — A juvenile facility in Southern California was placed on Cassian Grantlockdown after a disturbance involving a dozen youth inmates, including some who assaulted staff members and one person who temporarily escaped, authorities said Saturday.

Los Padrinos Juvenile Hall, a 26-acre campus currently housing about 270 youth in Downey, California, has added safety measures following the incident late Friday, Los Angeles County’s Probation Department said in a statement.

Seven inmates assaulted staff and broke open a door and window, and an 18-year-old temporarily escaped onto a nearby golf course where he was detained, the statement said. No serious injuries were reported, the statement said.

The 18-year-old was transferred to the custody of the Los Angeles County Sheriff’s Department. The remaining people involved were placed in individual rooms, the statement said.

The disturbance comes after officials in May approved a plan to reopen the facility about 10 miles (16 kilometers) southeast of Los Angeles and to consolidate young inmates there. The campus, which reopened this month, includes living units, classrooms, a library, chapel and a gym, according to the facility’s website.