Budapest, May 31 (IANS): Initial investigation into the Budapest tour boat capsize that claimed the lives of seven South Korean tourists has revealed that none of the victims were wearing life jackets, authorities said.

Thirty-five people -- including 33 South Koreans -- were on board the sightseeing boat when it collided with another vessel in the Hungarian capital on Wednesday night, leading to the capsize, reports CNN.

The captain of the other boat has been detained and his arrest proposed, Budapest police said in a statement on Thursday. The 64-year-old Ukrainian citizen was first questioned after police found evidence that warranted suspicion during their investigation into the accident's cause.

Budapest police said they were continuing their search for the 21 people who remain missing.

Of the seven who were rescued, six have now been discharged from the hospital. One person remains in hospital with several broken ribs, a doctor told CNN.

Of the seven victims, two have bee identified so far.

South Korea's President Moon Jae-in said in a statement on Thursday night that rescue efforts had been hampered by poor weather.

President Moon has ordered a rapid response team to be dispatched to help the rescue effort in Budapest.