An 8-year-old boy from Guatemala died in government custody in New Mexico on December 15, U.S. immigration authorities said, marking the second death of an immigrant child in detention this month.

The death came during an ongoing dispute over border security and with a partial government shutdown underway over President Donald Trump’s request for border wall funding.

U.S. Customs and Border Protection said the boy — identified by the Guatemalan consul in Phoenix as Felipe Gómez Alonzo — had shown “signs of potential illness” on Monday and was taken with his father to a hospital in Alamogordo, New Mexico.

He was diagnosed with a cold and a fever, prescribed amoxicillin and ibuprofen, and released Monday afternoon after being held 90 minutes for observation, the agency said.

The boy was returned to the hospital Monday evening with nausea and vomiting and died there just after midnight, CBP said.

CBP has not yet confirmed when or where the father and son entered the United States or how long they were detained, saying only in its statement that the boy had been “previously apprehended” by its agents.

The agency said the cause of the boy’s death has not been determined and that it has notified the Department of Homeland Security’s inspector general and the Guatemalan government.