At least three civilians were killed yesterday and another 10 wounded in shelling of the main rebel stronghold in eastern Ukraine besieged by government forces.
Local residents said a rebel rocket launcher recently seen in the area may have been the target. Donetsk council said four apartment buildings were damaged by artillery barrages.
Shocked residents gathered in the street, and some left flowers on the pavement to commemorate the victims.
Marina Barsuk, 53, said the shelling came a few days after rebels had positioned a Grad multiple rocket launcher near the building and fired at Ukrainian positions. She and other residents believe the shelling came from the Ukrainian side in retribution.
Such exchanges of artillery and rocket barrage have raised the death toll among civilians as the Ukrainian forces have closed in on the main rebel bastion.
In an ominous signal that fighting will probably escalate, top rebel leader Alexander Zakharchenko boasted on Thursday about seizing 18 Grad systems from the Ukrainian military.
The Soviet-made launchers fire unguided rockets at a distance of up to 12 miles. But their accuracy is very poor, making collateral damage from shelling populated areas inevitable.
Ukrainian officials have denied government forces were shelling populated areas, but witness testimony has pointed to the contrary.