"Two civilians were killed as a result of shelling in Dzerzhynsk," about 50 kilometres (30 miles) north of the rebels' de facto capital Donetsk, representative of the region's Kiev-appointed administration's health department told AFP.
The city hall of the nearby town of Gorlivka reported two civilians killed and another four wounded, including two children.
It remained unclear which side was responsible for most of the casualties, with both Kiev's pro-Western forces and the fighters exchanging blame.
The United Nations estimates the conflict has killed more than 6,800 people from April, 2014.
In February, a peace deal reached in Minsk called for the withdrawal of heavy arms from the frontline. The shellings continued, although the region in which daily attacks continue has grown smaller over time.
