WASHINGTON — A 16-year-old Guatemalan boy who was placed in a Texas shelter for migrant children and teenagers after entering the United States has died in federal custody, officials said on Wednesday.

The boy, who died on Tuesday, was considered an unaccompanied minor who had entered the United States. Officials refused to comment on how long he had been in the country, where his parents were or whether he entered illegally. But his death is sure to highlight the risks for the surge of Central American families who have crossed the southwestern border in recent months, overwhelming federal facilities and resources.

The death of the boy was first reported on Wednesday by BuzzFeed.

It was the third death of a migrant child from Guatemala in federal custody in recent months. The first two had been held in Border Patrol facilities intended for adults before they were taken to hospitals, where they died.

The 16-year-old boy had shown signs of illness while in a shelter that was managed by the Office of Refugee Resettlement, which handles the care of migrant children, said Evelyn Stauffer, a spokeswoman for the Administration for Children and Families.