KIEV

The death toll from Saturday's shelling in the southeastern Ukrainian city of Mariupol rose to 15 as five more victims succumbed to their wounds, Ukrainian Interior Ministry said. 

According to the ministry, the artillery attack killed at least 15 people while injuring 41 others. 

"Putin is responsible for this bloody attack and all the pain of Ukrainian people," the National Security Council of Ukraine said in a statement after the attack. 

Regional sources said the shelling had hit a multi-story building in Vostochny district, causing several fires in nearby apartments.

Tensions increased Wednesday when Ukraine's military confirmed it had abandoned Donetsk Airport to pro-Russian separatist militias. 

On Thursday, at least eight people were killed and 13 others were wounded after two mortar rounds landed near a crowded bus station in Donetsk, according to the Organization of Security and Cooperation in Europe, or OSCE.

More than 4,800 people have been killed since April last year after pro-Russian rebels seized parts of Luhansk and Donetsk.