The decomposing bodies of two young children, no older than toddlers, were found wrapped in plastic bags and placed under a house, police said Wednesday.

The bodies were found late Tuesday by residents of a triplex who were trying to locate the source of a foul odor they had been smelling for as long as two weeks, police Sgt. Gabe Trevino said.

Investigators reported that one of the black plastic bags contained an infant wrapped in a blanket, according to a police report.

The medical examiner will determine the children's ages, gender and cause of death, but Trevino said police believe the children were between the ages of 6 months and 2 years.

Tina Vara, 27, said her 19-year-old sister lived at the house with her boyfriend and 5-month-old boy and 1 1/2-year-old girl. Family members said they had almost no contact with Valerie Lopez since she had started living with her current boyfriend, but friends reported seeing her looking as if she had been beaten up, Vara said.

They didn't know she had moved out until police called late Tuesday.

"She likes to keep secrets," Vara said of her baby sister, who had been running away since was 13 and had two other children in foster care. "She was a troubled kid."

Vara said her family first got word that police had found the bodies under her sister's house when they called her mother looking for information on Lopez.

Trevino declined to release any information about the people who lived at the house where the children's bodies were found, but he said police were looking to speak to them.

On Wednesday, the wooden house with chipping white paint was lined with crime scene tape as investigators carried items wrapped in brown paper from the house. Vara and other family members were gathered on the sidewalk near the house, holding a Christmas portrait of Lopez's daughter. They had only seen the infant boy when he was born.