The Danish Army reported that a civilian vessel called Ice Rose and a Russian frigate had collided in the Oresund Strait (Sound), between Denmark and Sweden.
There has been no pollution at all, and no one on board the boats has been evacuated, Lisbeth Jorgensen, duty officer at the Danish Armed Forces' operations centre, said.
"The Danish Maritime Accident Investigation Board is in process of collecting data to verify the sequence of events and to enable an analysis of the causes of the collision. This process will continue for several weeks", the head of the Danish Maritime Accident Investigation Board, Oessur Jarleivson Hilduberg, said.
The civilian vessel is reportedly a container ship, and there hasn't been an oil leak at the site, SVT reported.
Since the accident happened on the Danish side of the strait, Denmark is leading the investigation. The country has also reportedly asked for Sweden to help and the sea rescue has sent a couple of units and the coast guard to the site.
The Ice Rose is being watched to ensure that it can stay afloat safely. According to seafaring monitoring data, the Ice Rose was on its way from St. Petersburg to Gothenburg.