Texas: Three abandoned children and skeletal remains found at Houston apartments

Watch: 9-year-old has been dead inside SW Houston apartment for a year, 3 other kids were abandoned

Three abandoned children have been found alongside skeletal remains at a block of flats in Texas.

Authorities said the youngsters, aged seven, 10 and 15, were discovered at an apartment complex west of downtown Houston on Sunday.

The remains may also be those of a child, according to Harris County Sheriff Ed Gonzalez.

He described the situation as "heartbreaking", with the children having been living in "deplorable conditions".

NBC News, via affiliate network KPRC, reports that the children were found during a welfare check at an apartment.

A 15-year-old reportedly called and said his nine-year-old brother had been dead for a year and was in the next room.

The three children may have been in the apartment for months or even a year, Sheriff Gonzalez told the station.

"I haven't been told they were necessarily locked in, but at that age, it appears they were basically fending for each other," he added.

Skeletal remains, which may have been a sibling, were also found inside the apartment.

"We'd like to identify whoever are the parents, adults or next of kin," Mr Gonzalez said.

He added that the three children appeared malnourished and showed signs of physical injury.

All three have been taken to hospital for treatment.