( CNN ) -- Pro-Russian separatists fired rockets at a Ukrainian military camp in eastern Ukraine before dawn Friday , killing at least 19 troops , a Ukrainian military spokesman said . The attack happened around 4:30 a.m. near the town of Zelenopolsk , in eastern Ukraine 's restive Luhansk region , military spokesman Yuriy Stets said . At least 55 other people were injured , according to the nation 's counterterrorism office . The office of President Petro Poroshenko , whose country has battled separatists in the east for months , accused attackers of using Russian-made Grad rockets against Ukrainian armed forces . `` Militants will pay hundreds of their lives for each life of our servicemen , '' Poroshenko said . `` Not a single terrorist will avoid responsibility ; each of them will be punished . '' The European Union is sanctioning 11 more people over the Ukraine crisis , the European Council said Friday , bringing the total number subject to EU visa bans and asset freezes because of the crisis to 72 . The new names will be announced Saturday morning , the council said . Those already targeted include people in Ukraine and Russia , including Vyacheslav Ponomaryov , the self-declared mayor of Slovyansk , a rebel stronghold in the Donetsk region , and Vladimir Shamanov , commander of Russian airborne troops . CNN 's Victoria Butenko contributed to this report .
The violence occurred in the restive Luhansk region . Hide Caption 1 of 168 Photos:Photos: Crisis in Ukraine Crisis in Ukraine – The European Union is sanctioning 11 more people over the crisis .