More than 40 people are dead after a train and a bus collision in eastern Ukraine.

Investigators said the bus driver ignored the siren of the oncoming train, and the bus stalled on the tracks as the driver tried to shift gears.

Witnesses added that the driver also ignored a red light. There were no automated gates at the crossing.

"The driver violated traffic rules," said Lyudmila Bolshakova, spokeswoman for local police.

Forty-three people were killed in the crash, all of whom were on board the bus. Eight others were injured.

Ukraine's ombudsman Nina Karpachova cited crash survivor Dmytro Olyinik, 30, as saying the passengers tried to stop the driver from crossing the tracks.

They started screaming "Where are you going?" Olyinik was reported as saying.

Ukraine President Viktor Yanukovych declared a national day of mourning Wednesday. He said he plans to work with transportation officials to make the roads and railroad crossings safer.