Ten people on a river cruise were killed when their boat collided with a tugboat late on Monday in the Russian city of Volgograd, which is hosting matches in the soccer World Cup, rescue services said.
Emergencies services received notification at around 10 pm (1900 GMT) on Monday that the vessels had collided on the Volga river, about 1 km from the riverbank.
There were 16 people on board the pleasure craft, all of them Russians, the RIA news agency cited the local administration as saying.
In additional to the 10 dead, one person was missing and five had been rescued, Reuters reported quoting Emergencies Ministry spokesman Dmitry Ulanov.
Three of the survivors are in hospital, according to the website of regional governor Andrei Bocharov.
A search operation is under way, and an investigation has been opened into the cause of the collision.
Volgograd will host World Cup opening round matches involving England, Tunisia, Nigeria, Iceland, Saudi Arabia, Egypt, Japan and Poland.
The first is the June 18 game between England and Tunisia.