Illinois ? A man was arrested of charges of setting his cousin’s house on fire in western Illinois early Sunday and killing her five children, authorities and a relative said.

Four other people were injured in the blaze, including one who was airlifted to a Springfield hospital in critical condition, said Quincy police Sgt. Doug Schlueter.

The bodies of four boys and a girl – ages 5 months to 10 years – were found on the second story of the house, officials said.

Authorities said they arrested Zachary Q. Meeks, 27, after he was questioned about the fire that began around 3 a.m. in this community along the Mississippi River and about 90 miles west of Springfield.

Police released few details about their investigation at a Sunday afternoon news conference and would not cite a motive.