Moscow ( CNN ) -- The death toll has risen to seven in a boat collision Sunday in the center of the Russian capital , state media reported . A private boat carrying 16 people collided with a cargo barge on the Moskva River in Moscow then sank , according to Russia 's RIA-Novosti official news agency . The people onboard had been celebrating a birthday . Authorities have confirmed seven survivors . Two people are unaccounted for , the news agency said . Rescue efforts are under way , and a crane is expected to arrive at the site of the collision to help free the private boat , which is still wedged under water .
The boat was carrying 16 people attending a birthday party . The collision was on the Moskva River in Moscow . A crane is expected to arrive to help free the private boat , which is still wedged under water .