BUDAPEST, Hungary (AP) — Hungarian police have detained the captain of a cruise ship that collided with and sank a sightseeing boat packed with South Korean tourists on the Danube River in Budapest.

Seven people are confirmed dead and seven have been rescued, while 21 people remain missing in the waters.

Meanwhile, family members of those dead or missing were traveling from South Korean and expected to arrive Friday in the Hungarian capital.

Police said late Thursday they detained and questioned the 64-year-old Ukrainian captain of the larger vessel, who is suspected of endangering water transport leading to a deadly mass accident.

The group of 30 tourists, two guides and a photographer were on a sightseeing tour of Budapest when their boat collided with a Viking cruise ship during a downpour Wednesday evening.