Police are warning 11 Christchurch schools about a man who's been approaching female students

They say earlier this month, the man was riding a bicycle in Merivale and St Albans when he allegedly offered students cash in exchange for inappropriate favours.

He hasn't been identified and investigations are ongoing.

Detective Constable Andrea McDowell says they've sent a letter alerting 11 schools in the immediate area.

DC McDowell says they also want to encourage discussions around behaviours and actions that are inappropriate or that make a child feel uncomfortable