Seven were killed and 21 are still missing after a tourist boat carrying South Korean tourists capsized and sank in the Danube River in the Hungarian capital Budapest on Wednesday. /VCG Photo

According to local media reports, a total of 33 South Korean tourists and two Hungarian crews were on board when the boat was hit by another tourist vessel and then overturned on the river. /VCG Photo

The captain of the vessel was arrested by local police and was suspected of endangering water transport leading to the deadly mass accident, reported the Guardian on Thursday. /VCG Photo

Rescue efforts are still underway with boats, divers, spotlights and radar scanning along the river several kilometers downstream. /VCG Photo

South Korea's foreign minister, Kang Kyung-wha, a team of South Korean divers and dozens of relatives of those on board reportedly landed in Budapest on Thursday, reported the Guardian. /VCG Photo