The attacker has been named as Naida Asiyalova, 30, the Mail Online reported.
Dramatic footage from a dashboard camera in a car following the bus shows the explosion ripping through the vehicle, sending pieces of metal and glass flying.
The bombing in Volgograd – formerly Stalingrad – at 2pm on Monday led to more than 30 injuries, with at least half a dozen maimed.
‘According to preliminary information, a native of Dagestan, 30-year-old Naida Asiyalova, blew herself up,’ said a statement from Russian investigators.
‘She boarded the bus at one of the bus stops and an explosion took place almost immediately afterwards.’
‘It was a powerful explosion – a huge blast,’ said a father called Vladimir who rescued his daughter from the carnage. Many of the passengers were students.
‘The bus was torn to pieces. When I came to pick her up, half the bus was simply not there.’
Six people, in addition to the body of the suicide bomber were found according to Vladimir Markin, spokesman for the Investigative Committee, a Russian federal police agency. A further 28 were in hospital with eight in a grave condition.