"Since the beginning of the ceasefire, the first strike was carried out at night, on February 15, from militant positions in Stakhanov. A group of militants opened fire with howitzers," Tymchuk said.

"In addition, the militants attempted to move forward," he said.

At the same time, according to Tymchuk, the most difficult situation is seen at the Debaltseve bridgehead," Tymchuk said.

"Russian-backed militants and the Russian armed forces have actively attacked with artillery and fired Grad multiple launch rocket systems on the positions of the Ukrainian armed forces near Debaltseve. Most of the Grad strikes were carried out from firing positions near the village of Lomuvatka," Tymchuk said.

He also said that the fire was at some times more intense than that seen before the ceasefire was supposed to have come into effect at a minute past midnight on Sunday.