Ukraine's military says rebel violations of a cease-fire in the country's east are persisting, but have fallen off in recent days.

Military spokesman Lt. Col. Anatoliy Stelmakh told a briefing Wednesday that Russian-backed rebels shelled the village of Popasna twice during the night and also continued trying to overrun Ukrainian positions at the village of Shyrokyne, near the strategic port city of Mariupol.

In all, 19 artillery and mine attacks were recorded, he said.

"For a second day, we observe a reduction in shelling," Stelmakh said. "But the last day was not a cease-fire."

Ukraine says it will not begin a pullback of heavy weapons under a peace deal until the cease-fire firmly takes hold. Rebels said Tuesday they were beginning a pullback. The claim could not be confirmed.