Investigators have launched a criminal probe into the sinking of a pleasure boat in the Moskva River that killed at least seven people, the Moscow interregional investigative transport department said on Sunday. A private pleasure boat carrying 16 people sank on the night of July 30-31 in the Moskva River in the center of the Russian capital after a collision with a cargo barge. Six people were rescued and one swam to the shore on his own. The fate of two people is unknown. Tatiana Morozova, a spokeswoman for the Moscow interregional investigative transport department, said the investigation had been launched on the charges of violation of water transport operation rules entailing the death of two and more persons. The incident comes less than a month after a two-deck cruise ship Bulgaria carrying 201 people capsized and sank on the Volga River, killing 122 passengers, including children. Only 79 people were rescued. Following the sinking of the cruise ship Bulgaria, Russian President Dmitry Medvedev has ordered total checks of all passenger transport in the country.