Eight South Korean tourists dead, 21 still missing in Hungary boat accident

Hungarian police said on Thursday they have launched a criminal investigation into one of the country's worst boat accidents that left eight South Korean tourists dead and 21 others missing.

The "Mermaid" sightseeing boat sank late on Wednesday on the Danube river in the heart of Budapest after colliding with a larger tourist vessel and overturning on the river.

The accident happened near the Hungarian parliament, where the river has been flooding, with very strong currents, while a rainstorm enveloped Budapest.

"A criminal investigation has been launched. Police are investigating at the scene," police colonel Adrian Pal told a news conference.

Police showed security camera footage from a bridge that showed the two boats colliding.

"It sank within seven seconds," Pal said of the Mermaid.

The police said it may take days to lift the boat from the river bed and could not confirm or deny whether there could still be bodies trapped inside the hull. 

Authorities say prospects are minimal for finding the 21 missing people.

"I am not inclined to say there is no hope, so I would rather say there is a minimal chance (to find more survivors)," Pal Gyorfi, a spokesperson of the Hungarian national ambulance service, told state television.

"This is not just because of the water temperature, but the strong currents in the river, the vapour above the water surface, as well as the clothes worn by the people who fell in," he said in reply to a question about the search for the missing.

"The search is underway and we are still on the banks of the Danube river, but chances are minimal."

In Seoul, President Moon Jae-in said South Korea would work with the Hungarian government to investigate the cause of the accident.

"What's most important is speed," Moon told an emergency meeting, at which he urged the use of all diplomatic channels to ensure speedy search and rescue operations.

The foreign ministry said the South Koreans aboard the vessel when it sank were 30 tourists and three tour guides, in addition to a crew of two Hungarians.

Seven South Koreans were rescued, seven died, 19 were missing, and one Hungarian died, said Kang Hyung-shik, a foreign ministry official. The seven people rescued were suffering from hypothermia but stable, a Hungarian ambulance spokesperson said.

South Korea planned to send 33 officials to Budapest, including a emergency rescuers and military specialists, presidential spokesperson Ko Min-jung said, and the government would provide counselling to victims' families.

A massive rescue effort deployed boats, divers, spotlights, and radar scanning to scour the river for several kilometres downstream from the site of the accident, which took place soon after 9pm.

Journalists at the scene said they saw children's ambulances on the riverbank.

There was a six-year-old on board, said Lee Sang-moo, an official of the South Korean travel agency that booked the group tour. But the child did not figure on the list of survivors, the agency added.

The National Ambulance Service mounted searches along a stretch of the river downstream from Budapest and was on alert along a section further south in Hungary, where all boat traffic was halted.

Television images showed the bank of the Danube closed off by police on the Pest side, across from the World Heritage site of Buda Castle.

The Danube's flooding and currents made rescue efforts extremely difficult, a rescue diver told the state broadcaster, with water temperatures ranging between 10°C and 12°C.

The boat, the Mermaid, was a 27m double-decker river cruise boat with a 150-horsepower engine and could hold up to 60 people, its owner, Panorama Deck, told state media.

"We are mobilising every resource we have to protect human lives," it said, adding that the Mermaid had been in its fleet since 2003, with regular maintenance.

Boat registry Hajoregiszter.hu showed the ship, originally built in the Soviet Union in 1949, received a Hungarian-made new engine in the 1980s.

Neither the registry nor the operator could be immediately reached for comment on the boat's age.

A shipping expert told state television it was likely the pleasure boat had collided with a very large vessel that had sunk it very quickly.

The hull was found on the riverbed just a few hundred metres from its usual mooring point.