By CBSLA Staff

BAKERSFIELD (CBSLA) — The search for two young brothers continues two weeks after they disappeared from their California City backyard.

Orson and Orrin West were last seen in the California City backyard of their adoptive family’s home at about 5:45 p.m. on Dec. 21.

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(credit: National Center for Missing And Exploited Children)

Volunteers joined law enforcement over the weekend to help search for the boys in Bakersfield, where the adoptive parents lived before moving to California City. The FBI has reportedly also joined the investigation.

The family released a statement Monday on Medium, saying they have also engaged a team of private investigators in the search for the boys. The statement said the boys came to their adoptive family through emergency foster care after their birth mother’s parental rights were taken away by the state, and their fathers gave up their respective parental rights.

The West family says they have been threatened in the wake of the boys’ disappearance because they have not been involved in the physical search for Orson and Orrin.

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“…in less than 24 hours of the disappearance of the boys our extended family started receiving threats of physical violence including death threats,” the statement said. “In fact the boys home has been pelted with rocks, windows have been broken and vandals have attempted to break in.”

The family says they have been advised to avoid public spaces and crowds due to the threats, and that they are working to protect and shield the family’s four other children from violence.

Police have not named any suspects in the boys’ disappearance.

Orson is 3 years old and Orrin is 4 years old. Both are described as Black boys about 3 feet tall and approximately 30 to 40 pounds. They were last seen wearing black sweatshirts and gray sweatpants, and are believed to have left their home on foot.

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Anyone with information about the boys or their whereabouts can call 911 or the California City Police Department at (760) 373-8606.