A 7-month-old foster boy who was in critical condition after being injured died Friday.

"It is with great sadness that we announce today that a child in our foster care system has passed away," Tom Morton, director of Clark County Family Services, said in a statement.

Authorities refused to release the boy's name or any information about how the child was injured and said the matter remained under investigation.

"As the investigation continues, more information will be available," county spokeswoman Gina Olivares said.

The boy died about 1:30 p.m. Friday at a local hospital, said Capt. Terry Lesney of the Metropolitan Police Department's Crimes Against Youth & Family unit.

Police did not know the cause of death, but the boy had head injuries, Lesney said.

"We are continuing to work on the investigation," she said.

The boy was hurt Wednesday at his foster parent's house, in the 2700 block of Dune Cove Road, near Sahara Avenue and Fort Apache Road, police said.

The boy's foster mother called paramedics about 2 p.m., and when they arrived, they found that the child was not breathing, police said.

Authorities took the child to Summerlin Hospital Medical Center but then transferred him to either University Medical Center or Sunrise Hospital and Medical Center, police spokesman Jose Montoya said. He said he did not know which.

The boy had been living at the foster parent's house since January, said Lisa Teele, supervisor of the police's abuse and neglect unit.

Two other children, ages 2 and 3, also lived at the home. They were taken out of the home and placed in protective custody, police said.

Teele on Thursday said the two children were adopted by the family.

A next-door neighbor to the foster family, Kristen McGrath, said she has known the family for at least five years.

"They're just wonderful people," she said before the news that the boy had died. "I hope the boy is OK."

Clark County District Judge Douglas Herndon ruled in April that some information about foster children who die or are in near-death abuse and neglect incidents should be released. That includes the age of the child and whether county officials intervened.

But the county did not release information on the 7-month-old boy's case and said that it has not determined whether the child was injured because of an accident or because of abuse or neglect.

William Grimm, an attorney with the National Center for Youth Law, a child advocacy group in Oakland, Calif., who is a critic of the Nevada child welfare system, said more information should be released about how the boy died while in foster care.

"This is a tragedy, and I hope that all the details surrounding the death will become a matter of public record and discussion," he said.

About 2,100 children are in foster care in Clark County. A majority of them are living with foster families.

A panel reviewed 79 child deaths in the state from 2001 and 2004 and found that 11 children in the county's custody had died.

The 2005 death of Adacelli Snyder, a 2-year-old who died of starvation after Family Services closed her case, and the June disappearance of Everlyse Cabrera, a 2-year-old who went missing after being placed with foster parents, also have been fueling the push for greater public accountability on the part of child welfare agencies.

Review-Journal writer Lisa Kim Bach contributed to this report.