Russian rockets struck a passenger train in a station in eastern Ukraine on Wednesday, killing at least 15 people and wounding 50 more, President Volodymyr Zelenskyy said.

In a video address to the United Nations Security Council, Zelenskyy said the rockets had hit the train in the small town of Chaplyne, some 90 miles west of Donetsk. Four carriages were on fire, he said.

Ukraine marked its independence day on Wednesday and Zelenskyy had warned ahead of time that Russia might try to disrupt the celebrations.

"Four passenger wagons are now on fire. As of now, at least 15 people have been killed and around 50 people have been wounded," Zelenskyy said.

"Rescuers are working, but, unfortunately, the death toll could increase."

Russia has repeatedly denied its forces are aiming at civilian targets. In April, at least 57 people died when Russian missiles hit the train station in the town of Kramatorsk, Ukrainian official said.