Police have stepped up patrols in the Cally after a man approached a 13-year-old girl in his car to ask how many boys she had been with and whether she wanted a lift home.

The teenager had been walking home down North Road at 9pm on Wednesday when the sex pest allegedly drove up to her in his Toyota Previa.

He also asked her how old she was, whether she knew where he could buy any cannabis and if she smoked herself.

Police have urged now parents to b be vigilant and remind their children to be careful and cautious.

The man is described as Asian, aged in his late 20s to mid 30s with short tidy black hair, and is thought to be 5 feet 6 inches tall.

A spokesperson for Scotland Yard said: "At this time enquiries are ongoing and no one has been spoken to in relation to this incident but it remains under investigation.

"Police will have extra reassurance patrols in the area this afternoon and for the rest of the week.

"We remind students, parents and schools in the area to remain vigilant."

Anyone with information relating to the incident is asked to call the police on 101 or Crimestoppers on 0800 555 111.