The children were found at a family member's home in California City and have been placed in the care of the Department of Children and Family Services, according to the Los Angeles County Sheriff's Department's Palmdale station.
Authorities said the children's parents were arrested on unrelated charges. Before the brothers went missing, the parents missed a court date which sparked DCFS to search for the children, authorities said.
The four boys were previously last seen around 2 p.m. July 1 in the 800 block of East P-12, and investigators suspected at the time they were taken to Mojave, according to the Sheriff's Department.
Deputies identified the siblings as 4-year-old Kase Brown, 4-year-old Kai Brown, 2-year-old Kay'den Brown and 5-year-old Koen Brown. Kase has Down syndrome, sheriff's officials said.
City News Service contributed to this report.