The youngsters made the 13 calls to police fire and ambulance services on Saturday.
Officers were able to track down the family where the calls were being made from, and able to speak to the parents about the dangerous consequences of hoax calls - and are now urging parents to ensure other children don’t make the same calls.
A Cambridgeshire police spokesman said: “The calls were from a group of children laughing and asking to order a pizza from us. This resulted in the 999 line becoming so busy that genuine emergency calls couldn’t get through.
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“Because of this, officers were deployed to the house where the mobile was being used in Peterborough and knocked on the door of the parents house.
“Innocently, the parents said their children hadn’t and wouldn’t make any hoax calls so officers retreated back to HQ and plan B was created.
“Our call handlers cleverly called back the mobile number later on in the evening when the children would most likely be asleep, to explain to the parents exactly what had been going on.
“To their horror, the children had requested pizza from police, ambulance and fire services .
“The parents were given stern words of advice and were told the impact the calls had on the emergency service we provide.
“We know its hard to keep eyes on the little ones, but please take the time to educate your children on the seriousness of hoax calling emergency services. You can find out more information and advice by visiting https://bit.ly/34POmz9