At least 15 people have been killed in a collision between a bus and truck in Russia, officials said.The accident took place on a highway connecting the cities of Yoshkar-Ola and Kozmodemyansk in the Russian Republic of Mari El, Russia's Ministry of Emergency Situation said in a statement on Thursday, Xinhua reported.Fourteen people were killed at the scene of the crash and one woman died on the way to hospital, Interfax news agency reported, citing the Republic's Interior Ministry.Rescue teams sent by the Emergencies Ministry and other emergency response services were working at the accident scene, the statement said. All the injured were hospitalised, it added.An investigation into the accident was underway. Police believed heavy snow may have caused the collision.