Danish police said they have searched a port and a ferry in northern Denmark after a tip off that the main suspect in the truck attack in Berlin had been sighted there, but the search did not yield any result.

“Our assessment this morning is that nothing suggests he is or has been in Grenaa,’’ police spokesman Klaus Arboe Rasmussen told newsmen.

“Police acted on information received late Wednesday,’’ the police spokesman added.

Police deployed a helicopter as well as officers, and dog patrols.

Rasmussen said police patrols would remain in the area as the Europe-wide search continued for 24-year-old Tunisian Anis Amri.

A Stena Line passenger ferry was delayed for several hours as all passengers and vehicles were checked before it was allowed to leave for Varberg, western Sweden.