At least seven people have died and 19 are missing after a boat capsized on the Danube river in Hungary’s capital Budapest, state media reported.

Thirty-three people, mostly tourists from South Korea, were on board the boat when it was hit by another vessel while moored, the MTI news agency said.

The incident occurred at about 22:00 local time (20:00 GMT) on Wednesday.

The Danube river, a popular draw for tourists, had swelled due to heavy rainfall, causing strong currents.

The boat that sank was identified as the “Hableany”, or Mermaid. The vessel has two decks and a capacity of 45 people for sightseeing trips.

South Korea’s foreign ministry confirmed that 19 Koreans were missing, and said the government planned to send a team of officials to Hungary.

A large rescue effort continued into the early hours of Thursday, with boats, divers, spotlights, and radar scanning along the river several kilometres downstream.

Rescue teams warned that as more time passed the strong currents would carry people further downstream, lessening the chances of finding survivors.

The National Ambulance Service was conducting searches downstream from the central Budapest area and boat traffic was halted on the entire Danube south of Budapest, Reuters news agency reported.