POKROVSK, Ukraine (AP) – Russian and Ukrainian troops engaged in close-quarter combat in an eastern Ukraine city Sunday as Moscow’s soldiers, supported by intense shelling, attempted to gain strategic footholds for conquering the region in the face of fierce Ukrainian resistance. Ukrainian regional officials reported Russian forces “storming” Sievierodonetsk after trying unsuccessfully to encircle the city. The fighting knocked out power and cellphone service, and a humanitarian relief centre could not operate because of the danger, the mayor said.