Two 14-year-old girls are recovering after two men indecently assaulted them at a beauty spot where they were swimming.
The friends were attacked on Sunday on the banks of the River Meon, on River Lane, near Wickham in Hampshire.
They desribe the suspects as aged between 15 and 30, with tanned skin.
The men were driving a small white van with two rear windows, which were barred.
Detectives have cordoned off an area around the riverbank while they search for clues.
Police are appealing for witnesses to the attack to contact them urgently.