Police are asking parents to talk to their children after a man was charged with sexually assaulting four girls because they believe other victims have yet to come forward.

Luis Walther Carrillo Hernandez was charged earlier this month with four counts of sexual assault that allegedly took place in Longueuil and in Montreal.

According to Longueuil police in each instance he approached girls aged 8 to 14 walking alone or in pairs, touching himself and then touching the bottom of a girl. In each case no adults were around.

"He did it in residential streets but also commercial streets, so it was a crime of opportunity I think," said Const. Melanie Marcille.

In each case the suspect immediately ran off, frequently getting into a grey Toyota Corolla and driving away.

Const. Marcille said the first incident took place six months ago, and that three incidents took place since then.

Police believe victims may not have thought it was important enough to tell their parents or authorities--but they would like that to change.

"We ask parents to look on our Facebook site and to look at the picture of the suspect and the description, and maybe their child will remember this man and remember that he touched [them]," said Const. Marcille.

She said that children should also walk in well-lit areas, try not to walk alone, and to be wary of strangers.

Carrillo Hernandez remains in custody and his next court appearance is on May 31. The charges against him have yet to be proven in court.

He is 40 years old and stands 1.7 m (5'7") and weighs 82 kg (180 lb).

He has brown hair and brown eyes, and speaks French with Spanish accent.

Anyone who believes that Carrillo Hernandez approached them is urged to contact Echec au Crime online or by calling at 1-800-711-1800.