A Ukrainian tank stands in the yard of an apartment block in Avdiivka, eastern Ukraine, Wednesday, Feb. 1, 2017. Heavy fighting around government-held Avdiivka, just north of the rebel-stronghold city of Donetsk, began over the weekend and persisted into early Wednesday. The Contact Group called for the opposing sides to cease fire and urged them to pull back their heavy weapons by the end of the week. (AP Photo/Evgeniy Maloletka)