A 15-year-old girl from Cleveleys has been sexually assaulted close to the Promenade in Blackpool.
Detectives said the teenager was walking home along Princess Way close to the Promenade when she was attacked on Saturday around 10.30pm.
An investigation has now been launched and the youngster is being supported by specially trained officers, police said.
A Lancashire Police spokesman said: “This was a particularly distressing incident for the 15-year-old girl and she is being supported by specially trained officers.
“An investigation is continuing and if anybody has any information about this incident, they are urged to contact police on 101.”
A 28-year-old man arrested on suspicious of sexual assault has been bailed pending further inquiries.