Authorities in Maryland say two children taken into custody while walking home without an adult last year have been picked up again.

Montgomery County police say officers responded to a call to check on children without an adult at a Silver Spring park Sunday afternoon and took the children to Child Protective Services.

Meanwhile, the children's mother, Danielle Meitiv, says they began searching for her 10-year-old son and 6-year-old daughter, who were expected home at 6 p.m. She says they didn't learn where the children were until 8 p.m.

Police say no charges have been filed but the matter remains under investigation.

The case prompted debate on so-called "free-range parenting." Meitiv says to get their children back she and her husband had to sign a safety plan that forbids leaving the children unattended.