Police in Western Pennsylvania are searching for a young infant last seen Thursday in Washington County. The child's grandparents are pleading for his return.

Ambrose Klingensmith, who is seven weeks old, is believed to have seen in a car with parents Daemon Klingensmith, 23, Jeannette Funnen, 32, and a 3-year-old boy Makias Palmer. Authorities advise people to be on the lookout for the vehicle: a gold and silver 2001 Buick Century, with a Pennsylvania license plate reading LBD6681, according to the Pittsburgh Post-Gazette.

West Mifflin Police could not confirm to International Business Times that Palmer is Funnen's son, though some local reports have noted that he is her son.

(An officer with the West Mifflin Police Department confirmed to IBT the spelling of Jeannette Funnen's last name. There were previous spellings of Funner.)

As of Saturday, the FBI has joined in on the search for Klingensmith, according to local reports. The child was believed to have been taken by his parents from a children’s hospital Thursday. The infant was being examined for stomach injuries and fingermark bruising believed to be the result of child abuse. He was taken away by his parents before doctors could finish evaluating him.

Kimberly and Eric Klingensmith, the child’s grandparents, don’t believe their son would have intentionally hurt the child.

“I think they have an idea in their head that the kids are going to be taken away from them, and they’re never going to see them again,” Kimberly Klingensmith said.

“Bring the kids home let us take care of them. We’ll work through what you have to work through, so you can get your kids back. It’s a process you’ve got to go through it,” Eric Klingensmith said.

The grandparents are also concerned for Funnen's mental wellbeing, believing that she may require medication. The child’s mother is believed to have attempted suicide during two prior pregnancies. Two other children have in the past been removed from her care and custody.

Anyone who believes they have seen this child is advised to contact 911 or the West Mifflin Police at (412) 461-3125 with the information.

Missing case
A bag to collect forensic evidence is seen as the New York City Office of Chief Medical Examiner hosting DNA Extraction demonstration to unveil groundbreaking technology in New York, on Sept. 6, 2018. Getty Images/ANGELA WEISS