Sunday’s accident happened three kilometers (two miles) from the shore near Syukeyevo village in Tatarstan, some 800 kilometres east of Moscow.

The boat sank at one of the widest points of the river — just downstream from a reservoir that stretches more than 20 kilometres from shore to shore.

The boat was likely filled far beyond capacity of around 140 passengers, with up to 199 people on board, emergency ministry officials estimated.

Many people on the list of survivors and victims did not have tickets.

Rescuers and passing boats picked up some 80 people from the river leaving more than 100 unaccounted for.