The death toll from a Russian rocket attack that hit an apartment block in eastern Ukraine over the weekend rose to 18 on Monday and rescuers were still racing to reach survivors in the rubble, the emergency services said.

Rescuers were in voice contact with two people trapped in the ruins of the five-storey block in the town of Chasiv Yar in Donetsk region that was struck late on Saturday, the service said.

"As of 08:45 on July 11, ... 18 people were killed, 6 people were rescued from the rubble, about 137 tonnes of rubble were cleared...," it said.

Russia, which invaded Ukraine in what it calls a special military operation, denies targeting civilians. (Reporting by Aleksandar Vasovic Writing by Tom Balmforth Editing by Catherine Evans)