BUDAPEST, Hungary (AP) — Preparations for salvage efforts of a sunken tour boat in the Danube River have resumed in Budapest.

A diver could be seen Monday morning entering the water from a pontoon in the river, holding on to a ladder in the river as other adjusted his air hose and other equipment.

The Danube's fast flow, its high springtime water levels and near zero visibility under water have prevented divers from reaching the sunken boat so far.

The boat carrying South Korean tourists capsized and sank Wednesday night after colliding with a much larger river cruise ship near the Hungarian Parliament building.

Seven of the 35 people on board have been rescued, with seven confirmed fatalities and 21 people, including 19 South Koreans and the two Hungarian crew members, still missing.