As many as 40 people were killed and 12 others were injured when a bus collided with a train locomotive on Tuesday morning in the Dnipropetrovsk region in eastern Ukraine, Prime Minister Mykola Azarov said.

"The accident took place this morning at 9 a.m in Dnipropetrovsk region. A bus collided with a locomotive at a unguarded intersection," a railways spokesman was cited by the Interfax- Ukraine news agency as saying.

The spokesman gave no more details.

"An alarm system was working. It means that the move was closed," the spokesman noted.

"The bus driver ignored the traffic signals," he added.

President Viktor Yanukovych conveyed his condolences to the relatives of the victims and said a committee headed by Deputy Prime Minister Andriy Kluyev had been set up to investigate the cause and help the families.

A statement on the presidential website said Kluyev had already left for the scene of the tragedy.

"The head of state has ordered law enforcement agencies to carry out a detailed investigation to establish those responsible for the accident," the statement said.