Efforts remain underway to find the missing 19 South Koreans and two Hungarians who were aboard a sightseeing boat when it collided with another vessel and sank in the Danube River in Budapest on Wednesday.

According to local media reports on Thursday, Hungarian rescue authorities are actively searching for the missing passengers of the 27-meter-long double-decker ship called the "Hableany.” 

The boat was carrying 33 South Koreans when it sunk, of whom seven have been rescued and another seven are confirmed dead.

Hungarian disaster management authorities said they mobilized close to 100 firefighters as well fire trucks and other equipment in efforts to aid the search for survivors.

Some media outlets have reported that dozens more police, military forces, and underwater specialists have been mobilized as well.

However, search and recovery efforts have been encumbered by fast-flowing currents and heavy rains in recent weeks.