DONETSK, Ukraine — Ukraine's Interior Minister said Tuesday that 30 pro-Russian insurgents were killed during government operations to expunge anti-government forces in and near a town in the east.Arsen Avakov said on his Facebook page Tuesday that four government troops also died and another 20 were injured during fighting in Slaviansk.Gunbattles took place at various positions around the city in what has proven the most ambitious government effort to date to quell unrest in the mainly Russian-speaking east.In Donetsk, a major city some 120 kilometers south of Slaviansk, flights from the local airport were suspended Tuesday.Avakov said Monday that pro-Russia forces in Slaviansk, a city of 125,000, were deploying large-caliber weapons and mortars in the region and there were injured on both sides. Government troops were facing about 800 insurgents, he said.Ukraine is facing its worst crisis in decades as the polarized nation of 46 million tries to decide whether to look toward Europe, as its western regions want to do, or improve ties with Russia, which is favored by the many Russian-speakers in the east. Dozens of government offices have been seized, either by armed insurgents or anti-government crowds, over the past several weeks.The goals of the pro-Russian insurgency are ostensibly geared toward pushing for broader powers of autonomy for the region, but some insurgents do favor separatism.