A man in a clown mask has stabbed a teenager in western Sweden, police have said, according to BBC News.

The youth was left with minor injuries following the attack, which happened when he went outside for a cigarette in Varberg, south of Gothenburg.

It came the day after two people in clown costumes reportedly threatened to kill a woman in central Sweden.

The reports are the latest in a wave of "creepy clown" sightings in Europe and the U.S.. The craze involves adults in frightening outfits scaring passers-by.

Police are still searching for the Varberg clown, but are not yet willing to definitely link it to the craze, which began in the U.S. over the summer.

The teenager suffered minor injuries to his shoulder.

"We do not know what prompted this. It was not a robbery, and I do not know if they had fought before," spokesman Ulla Brehm told Gotesburgposten (in Swedish).

"It's hard to say if this is something that has to do with the trend that has come from the U.S., but there was a clown mask on the site."

However, Swedish Interior Minister Anders Ygeman has called for calm as more and more sightings of scary clowns are made across Sweden.

"We don't want to see a situation where a person gets into real trouble because someone, perhaps half joking, puts on a clown mask," Ygeman told the TT news agency.