Four children taken to hospital after eating cannabis laced sweets are not thought to have suffered any long-term effects, police said.

But Surrey Police said the youngsters were “lucky” not to have been more seriously affected by whatever they ate, and the source of the sweets was still being investigated.

Emergency services were called to the parade of shops in Pound Lane after a 12-year-old boy and girl, as well as a 13-year-old boy, were vomiting uncontrollably and falling in and out of consciousness.

Another 12-year-old boy was taken to hospital by his family as a precaution because he is also believed to have eaten the sweets.

But the force said that one of the 12-year-old boys had been discharged late on Saturday and the other three children were expected to be released from hospital on Sunday.

The incident comes after a string of incidents in the southwest London area in recent weeks, with children hospitalised in similar circumstances in Merton and in Sutton.

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Detective Sergeant Lisa Betchley said: “These children were incredibly lucky that they were not more seriously affected by whatever it was that they ate – and this is thanks, in great part, to the prompt actions of two medical students who happened to be nearby and assisted in the early stages, as well as the South East Coast Ambulance Service and hospital staff for their rapid response and treatment.

“We are still investigating where the children obtained these sweets from, and are still keen for any information that may help us identify the specific source of the sweets in this case.

“I’d also ask anyone who has these types of products to think about how they store them and who could access them – consider the impact should these sweets come into the possession of younger children who have no knowledge of their contents.”

It is believed the sweets may have been supplied to the children at the nearby Court Recreation Ground.

Police do not have a clear description of the sweets involved, although a similar report from Friday night involved “jelly apple rings” which resemble green jelly circles.

The force has also urged parents in Epsom to “urgently” speak to their children about the dangers of “edibles” – cannabis-based food products.

Anyone who is concerned about the health of someone that they believe may have taken these products is asked to call NHS 111 or 999 in an emergency.

Anyone with information about the supply of these sweets or who has found similar sweets or related packaging in the area local to Court Recreation Ground is asked not to destroy them but to contact Surrey Police via the online chat on www.surrey.police.uk quoting reference PR/P21090934.