At least 30 pro-Russian separatists were reportedly killed on Monday as the Ukrainian government ramped up its efforts to reclaim the city of Slovyansk. Some reports say as many as 34 are dead. At least four Ukrainian soldiers were killed in gun battles with pro-Russian forces. Ukrainian Interior Minister Arsen Avakov posted this information on Facebook on Tuesday, adding that pro-Russian forces were using large-caliber weapons and mortars. The clashes marked Ukraine’s latest and most ambitious attempt to regain control of the eastern cities that fell to pro-Russian insurgents.