SUPERIOR, Ariz.— The mother of a baby and a toddler was arrested on suspicion of first-degree murder after the children were found dead in car seats inside a car, officials said Tuesday.

The bodies were found outside the family’s home in the historic mining town of Superior, a community of about 2,900 people about 60 miles east of Phoenix. Autopsies were being conducted to determine causes of death of the 2-year-old boy and 10-month-old girl.

The mother was identified as Brittany Velasquez, 20. She was jailed, and authorities did not know whether she had a lawyer who could comment on the allegations, said sheriff’s spokeswoman Navideh Forghani. The names of the children were not immediately made public.

Some relatives of the children were inside the home when authorities went to crime scene late Monday night, but Forghani said she could not provide information about the circumstances of how the children were placed or left in the car or a motive into their killings.

ASSOCIATED PRESS