LIVINGSTON, Texas — Texas authorities said Tuesday they were planning to give the public “significant” updates in the search for an 11-year-old girl who has been missing since she failed to get on a bus for school last week.

The family of Audrii Cunningham reported her missing last Thursday after she didn’t return to their home from school in Livingston, located north of Houston. Investigators later discovered that she’d never gotten on the bus to go to school that morning.

A news conference was scheduled for Tuesday afternoon.

Authorities on Friday arrested a man described a person of interest in the case on an unrelated assault charge. The man is a friend of the girl’s father and lived in a camper on the family’s property near Lake Livingston.

Texas Dept of Public Safety spokesman Craig Cummings said Audrii lived with her father, grandparents and other family members.

A backpack that authorities believe belonged to the child was found Friday near the dam on Lake Livingston, one of the state’s largest lakes.