Russian shelling of the eastern Ukraine town of Sloviansk on Monday killed at least two people and wounded more than two dozen others, authorities said.

"As of 13:00, there are two dead and 29 wounded in Sloviansk," Donetsk region governor Pavlo Kyrylenko said on Facebook.

He added that "administrative and office buildings, five high-rise buildings and seven private houses were damaged" in the attack.

"(Russian forces) struck the city centre around 10:30 (0730 GMT) with two S-300 missiles," he added.

Kyrylenko also said that another town in Donetsk region, Druzhkivka, was targeted by an attack.

"Two S-300 missiles hit the Druzhkivka orphanage and almost completely destroyed it," he said, adding that according to initial information there were no casualties.

"Another day that began with terrorism by the Russian Federation. The aggressor state shelled our Sloviansk," Ukraine's President Volodymyr Zelensky said on social media.

"The enemy must know: Ukraine will not forgive the torturing of our people, will not forgive these deaths and wounds," he added.

Russian forces have made the capture of the Donetsk region their main military priority and claimed to have annexed the region last year despite not fully controlling it.