North Yorkshire Police has again tweeted to ask parents to keep their children indoors. 

In a tweet, it said: "This is so important. If you're parents and your children are not at home - found out where they are and get them home. They should not be socialising. The school are shut in order to protect them. Do your part please."

The message comes just two days after the force said it was called to several reports of groups of children throughout York