Fighting is still raging on the outskirts of the rebel stronghold of Donetsk in eastern Ukraine despite peace talks this week.

Russia and Ukraine agreed in Berlin on Monday to call for the pullback of smaller-caliber weapons from the front lines of the conflict that has claimed more than 6,000 lives.

On the ground, however, even the previous agreement that called for a cease-fire and a withdrawal of heavy weaponry appeared to be shaky.

Heavy shelling was heard in Donetsk late evening and in the early hours on Tuesday. Rebel mouthpiece Donetsk News Agency reported one rebel fighter dead and five wounded in the overnight clashes.

Fighting appears to be focused on the now-obliterated Donetsk airport and the village of Shyrokyne by the Azov Sea in the south.