Seven South Koreans and one Hungarian have died and 20 others remain missing after a boat carrying close to three dozen South Koreans sank in the Danube River in Budapest on Wednesday.

Seoul’s Foreign Ministry says 33 South Koreans were aboard a sightseeing vessel when it collided with another boat and sank in the downtown Budapest portion of the river.

The ministry said the incident occurred around 9 p.m. local time, and that everyone on board was a South Korean national save for two Hungarians. It added that seven people were rescued and 20 remain unaccounted for, including one Hungarian.

Search and recovery efforts remain underway, but have been hampered by fast-flowing currents and heavy rain​.  

The vessel that sunk is a 27-meter-long double-decker called the "Hableany," and has a 60-passenger capacity. It has been in service and received regular maintenance since 2003, according to its operator Panorama Deck.

The South Korean embassy in Hungary has formed a task force and is cooperating with local authorities and providing assistance at the site of the accident.

[Photo : YONHAP News]