The victims were enjoying a catamaran ride along the Volga River in Volgograd when their vessel struck a barge, killing most of the 16 revellers on-board who were celebrating the birthday of a local policeman.
Five people were rescued from the unlicensed boat, which sunk moments after the collision.
The tragedy occurred a mile away from where England is due to play Tunisia in the World Cup on Monday, with fans already starting to arrive in the city.
It is understood no foreigners were involved in the horrific accident some 800 feet off the city’s main river embankment.
Six women, a teenage girl, and four men were killed including Vitaly Negrash, whose birthday the group was celebrating, and his wife Elena and daughter Inga, 17.
Safety concerns were expressed after reports the catamaran was overcrowded with 16 on board when it had a capacity of only a dozen, and it had no lights and insufficient life jackets. The vessel was not registered and had no licence to carry passengers, said local reports.
It collided with barge Kapital Vecherkin. The captain and owner of the catamaran, Dmitry Khakhalev, a controversial former local politician once jailed for hooliganism and sexual violence, was among the dead. His female friend Anastasia Khakhaleva was also killed.