One of the ships is believed to be floating upside down, according to the administration
The collision occurred between Danish island Bornholm and the southern Swedish city of Ystad, SVT reported on Monday, citing the Swedish Maritime Administration.
The administration also added that one of the ships is believed to be floating upside down.
“We do not know exactly how it happened,” Jonas Franzen, communications manager at the Swedish Maritime Administration told national broadcaster SVT.
A rescue operation has been launched with boats from both Denmark and Sweden working on the spot.
“The rescue boats have heard screams in the water”, Mr Franzen told national broadcaster SVT. “The priority is to save lives”, he added.
More details are awaited