Seven people have been killed after a bus they were traveling in plunged into a river in St Petersburg, northern Russia, on Friday.

"The number of deaths as a result of a bus falling into the Moyka river has increased to seven people," Russia's Investigative Committee stated, updating an earlier toll.

PHOTO | COURTESY The bus 

It stated it had launched criminal investigations into the event.

The emergency ministry had stated that divers were connecting slings to raise the vehicle out of the sea.

According to authorities, around 20 passengers were on the bus when it crashed into the Moyka River in the old city core.

Russian media published video photos that appeared to depict the disaster. The footage shows the bus swerving fast down the road before colliding with a bridge and sinking in seconds.