Local residents inspect their home, which was damaged by last night's shelling in the village of Sartan, near Mariupol January 20, 2015.

Ukrainian soldiers came under attack from Russian regular forces in the north of the conflict zone in eastern Ukraine on Tuesday, a Ukrainian military spokesman said.

"Heavy fighting is continuing near the (Ukrainian army) checkpoints 29 and 31," the spokesman, Andriy Lysenko, said, referring to a part of Luhansk region near the border with Russia.

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"Ukrainian forces have stopped the advance of Russian troops ... The situation in the conflict zone is serious but under our control," he said at a special news briefing.