“Between 100 and 200 Swedes, most of them men, behaved in a rowdy manner in Helsingør and were sent away. The rowdiness continued on the ferry,” said police spokesman Mikael Persson.
Police said there were a lot of young people on board the vessel for the Walpurgis Night journey to Helsingborg in Sweded.
Back on Swedish ground, the troublemakers were met by police, resulting in the filing of five assault reports. Four of the alleged assaults took place at Kronborg castle in Helsingør and one on the ferry from the Danish town.
A 19-year-old man detained for minor narcotics offences is suspected of involvement in three of the alleged cases of assault.
Police said the trouble had not resulted in any serious injuries.