The Rotterdam police arrested a so-called "killer clown" on Wednesday after several people reported seeing him. The clown was wearing a mask and green gloves and carrying a blood-smeared plastic butcher knife, ANP reports. 

According to a police spokesperson, the police took action because the clown was scaring people. "If someone is carrying a firearm or weapon, we assume that it is real. If anyone intends to frighten others, then that is going too far. Then the joke is over", the spokesperson said.

Questioning revealed that the "killer clown" did not have bad intentions. "But we want to make clear that this is going too far", the police said. Nothing was said about the man's motives.

The killer clown phenomenon popped up in the Netherlands over the weekend. The first one was spotted in Almere over the weekend. So far this week there's been reports of killer clown sightings in Oss, Groesbeek, Zeeland and Limburg, according to ANP.

Killer clowns are people dressed as scary clowns that go about scaring bystanders. So far it seems that their intention is only to scare, not to actually attack anyone. The phenomenon started in the United States, but killer clowns have also been spotted in Australia and New Zealand.

On Wednesday fast food chain McDonald's decided to keep clown mascot Ronald McDonald out of public view for the time being.