Ukraine, Russian-backed rebels accuse each other of fresh attacks

A service member of the Ukrainian Air Assault Forces takes part in tactical drills at a training ground in an unknown location in Ukraine, in this handout picture released Feb. 18. Reuters-Yonhap

Ukraine's armed forces accused Moscow-backed rebels Saturday of launching a huge new wave of attacks that have intensified fears of a Russian invasion of its western neighbor.

The joint military command for east Ukraine reported 66 exchanges of fire by 7:00 am (local time) ― a high number compared to recent stages of the conflict ― while the rebels called the situation "critical.”

The statement said the rebels had resorted to using banned 82 and 120 millimeter-caliber mortar shells in towns across the front in the eastern regions of Lugansk and Donetsk.

"There have been no losses among members of the armed forces as a result of the enemy's attacks," it said.

"The armed forces control the situation and continue to perform their mission to rebuff and contain the armed aggression of the Russian Federation."

Ukrainian Army soldiers pose for a photo as they gather to celebrate a Day of Unity in Odessa, Ukraine, Feb. 16. AP-Yonhap

Moscow formally denies being involved in the conflict and calls it Ukrainian internal affairs.

But monitors from the OSCE European security body have reported regular shipments of Russian weapons across the border throughout the eight-year war.

The OSCE reported a massive 870 ceasefire violations across the conflict zone in its latest report Friday, which referred to incidents Thursday.

"In recent days, the OSCE Special Monitoring to Ukraine (SMM) has observed a dramatic increase in kinetic activity along the contact line in eastern Ukraine," the OSCE said in a statement.

Rebel leaders accuse the Ukrainian armed forces of trying to retake their two separatist regions by force ― a claim Kyiv denies.

The rebel leadership in Donetsk called the situation "critical," Saturday, and announced a "general mobilization.”

Leaders in the smaller separatist Lugansk region did the same about an hour later. (AFP)