More than 30 people were killed and over 100 were wounded in a Russian rocket strike on a railway station in east Ukraine on Friday as civilians tried to evacuate to safer parts of the country, the state railway company said.

It said two Russian rockets had struck a station in the city of Kramatorsk which is used for the evacuation of civilians from areas under bombardment by Russian forces.

"Two rockets hit Kramatorsk railway station," Ukrainian Railways said in a statement.

Kramatorsk was one of the stations still operating in Ukraine, and the governor of Donetsk said thousands of people were there at the time, trying to get on to trains out of the area.

Ukrainian Railways later added: "According to operational data, more than 30 people were killed and more than 100 were wounded in the rocket attack on Kramatorsk railway station."

Three trains carrying evacuees were blocked in the same region of Ukraine on Thursday after an air strike on the line, according to the head of Ukrainian Railways.