For six months now, battles have taken place in eastern Ukraine's Donetsk region, between the Ukrainian military and pro-Russian rebels, part of the self-declared Donetsk People's Republic. On September 5, both sides agreed to a cease-fire, but the shelling has continued in the weeks since, both sides blaming the other for violating the truce. Of the estimated 3,600 people killed in the fighting, more than 330 have died since the cease-fire was signed. Most of the current battles are taking place in a few neighborhoods of the city of Donetsk, primarily near the international airport. Several contingents of Ukrainian soldiers remain in control of the heavily-damaged buildings of Sergey Prokofiev International Airport, attacked constantly by rebel groups who surround them, and retaliating with outgoing fire. Donetsk city authorities said many residential buildings nearby had been destroyed and that two shopping centers had also been hit. Tensions between Ukraine and neighboring Russia remain high, despite a recent troop pullback by Russia and scheduled talks between Ukrainian President Petro Poroshenko and Russia's President Vladimir Putin later this week.