Parents should warn their children of “stranger danger”, police say, after two 13-year-old girls were stalked by men outside their Upminster school.

The students of Coopers’ Company and Coborn School, in St Marys Lane, ran into the school and contacted help before witnessing the two men enter a turquoise van and drive away.

One of the girls had noticed the same van in the area two weeks before the incident.

Havering Police are treating the report at around 4.45pm on October 22 as a “serious matter” and are asking parents to help protect their children.

Ch Insp Russ Taylor, of Havering’s neighbourhood policing team, said: “I would always ask parents to remind children about the importance of stranger danger and not talk to or go off with strangers.

“Equally, parents should ensure they are happy with their children’s whereabouts at all times. If any children know about any incidents where either they or a friend have been approached by a stranger in circumstances that cause concern, then they should contact police without delay.”

He added that any members of the public that may have seen the two suspects or the van should contact police immediately.

The school has written to parents to warn them of the incident that “caused alarm and is of concern”.

The first suspect is described as a white, bald male in his mid 20s. He is around 5ft 7in and of a medium build.

He was wearing a square, diamond earring in at least one ear and had a black leather jacket on with dark, ripped jeans and black footwear.

The second suspect is a white man with dark brown hair and in his late 20s. He was wearing a black hoodie with the hood up underneath a black, leather jacket and had black jeans on.

Anyone with information should contact Havering Police on 101 or call Crimestoppers anonymously on 0800 555 111.