Family members said the last time they saw Faye Marie Swetlik, she was getting off the bus in front of her home shortly before 4 p.m.
“At some point, the family realized they had lost track of her," Cayce Public Safety Officer Sgt. Evan Antley said. She said the family called 911 an hour later.
Chief Byron Snellgrove of the Cayce Department of Public Safety said they "are not ruling anything out."
“Faye is a bubbly and happy little girl,” her family said in a statement, Fox Carolina reported.
Police are using tracking dogs and stopping cars near Swetlik’s neighborhood in their search.
“We have more questions than answers,” Lexington County Sheriff's spokesman Capt. Adam Myrick, said. “But the top question we have right now is, ‘Where is Faye?'”
The Associated Press contributed to this report.