The St. Lawrence County Sheriff's Office issued an Amber Alert late Wednesday for Fannie Miller, 12, and her sister, Delila, 6. An intensive search for the missing girls was launched Thursday morning.
Investigators said the girls were last seen at the stand on Mt. Alone Road in Oswegatchie, a town on the St. Lawrence River. Witnesses said they saw someone putting something in the back of a white or light-colored sedan around 7:20 p.m.
The sisters were dressed in traditional Amish clothing, wearing dark blue dresses and aprons and black bonnets.
State Sen. Patricia Ritchie, a Republican who represents the area, visited the family Thursday morning. She said she spoke to the father.
"I can't believe something this horrible could happen in my backyard," Ritchie told WNYF-TV.