http://www.zerohedge.com/news/2014-09-20/military-plant-east-ukraine-devastated-massive-explosion-kiev-blames-accuses-russia-
Then, as ITAR-TASS reports,
Ukrainian media earlier in the day quoted Geletei as telling one of the journalists that the Russian army had delivered two tactical nuclear strikes on the Lugansk airport from a self-propelled Tyulpan 2S4 mortar system, thus causing the Ukrainian troops to leave the area.
“The strikes were so powerful that they demolished buildings completely from top to bottom,� media reports quoted him as saying.
Adn as Inforesist notes, this was confirmed by the Minister of Defense of Ukraine Valery Geletey during the return of the Ukrainian delegation from Poland.