Two young girls were indecently assaulted in separate weekend incidents.
Police are now appealing for witnesses as they try to track down the attackers.
The first incident occurred in Boyd Street, Falkirk, between 8.30 p.m. and 11.30 p.m. on Friday and involved a 15-year-old girl.
The following night, between 10 p.m. and 11.30 p.m. in a wooded area near Greenpark Drive, Polmont, a 14-year-old was the victim.
Officers are keen to speak to two women who were walking in Grahams Road on Friday night and may have spoken to the 15-year-old.
She was in the company of her 15-year-old friend and a man who is described as 16-20 years. He was wearing a white jersey, dark trousers and white shoes.
Police are following a positive line of enquiry in relation to the Polmont incident but are still appealing for information from witnesses.
Detective Inspector Douglas Anderson said: “We stress that these two incidents are not connected and we urge parents to ensure they know where their children are.
“Our advice to parents is to encourage their children to stick together when they are out and look after each other.”
Any information can be given to Central Scotland Police on 01786 456000 or anonymously to Crimestoppers on 0800 555 111.