Strong explosion shook city of Donetsk today (Apr 11, 2015). Explosion happened around 9 pm local time (4 pm EST). The wave of explosion reached all neighborhoods of the city. Some windows and door opened or closed, car alarms went off. Explosion wave took out windows in alley of Baku Kommissars in Donetsk. Reports are coming out that Ukraine has fired a SS-21 Scarab tactical ballistic missile on the city of Donetsk. self-defense forces were able to shoot it down over Kievsky neighborhood of the city near Donetsk airport.
Update: self-defense forces of Donetsk report that Ukraine fired a ballistic missile but it might not be an SS-21 Scarab; however, it is something similar to it, possibly a NATO counterpart.