Law enforcement, forest rangers and others resumed searching an upstate New York park on Monday for a 9-year-old girl who vanished during a camping trip over the weekend.

Charlotte Sena may have been abducted while riding her bicycle Saturday evening in Moreau Lake State Park, about 35 miles (60 kilometers) north of Albany, according to the state police.

More than 100 searchers, including police, rangers and civilians, scoured the park Sunday using drones, bloodhounds and an airboat.

The park remained closed Monday because of the search, and officials asked members of the public who showed up hoping to help to stay away and leave the search to professionals.

Charlotte, a fourth grader from nearby Greenfield, had been riding her bike around a loop in the bucolic park with other children when she decided to ride around one more time by herself. Her parents became alarmed when she failed to return after 15 minutes, Gov. Kathy Hochul said at a briefing Sunday.

The girl’s mother called 911 after her bicycle was found at around 6:45 p.m. Saturday.

Officials issued an Amber Alert on Sunday morning after an exhaustive search because “it was quite possible that an abduction had taken place,” state police Lt. Colonel Richard Mazzone said. The alert described her as a white girl with blonde hair and green eyes who is about 4 feet 6 inches tall (1.37 meters).

She was last seen wearing an orange tie-dye Pokemon shirt, dark blue pants, black Crocs and a grey bike helmet.