Police in Almere have warned parents to be on the look out for ‘horror clowns’ after receiving several reports of clowns with scary faces creeping up on children and carrying a knife.

People who spot a horror clown are being urged to phone the police emergency number. Police have also started a criminal investigation into the phenomenon, they said on Facebook.

‘We expect this is just a prank and the trend has blown over from America,’ the Facebook message said. The most recent sighting, on Monday, took place in the town’s Striphelden, or comic book hero, district.

The Netherlands was last in the grip of a horror clown craze in 2014, when they were known as crimiclowns –  a pun on the children’s hospital charity Cliniclowns.