Ukrainian Prime Minister Arseniy Yatsenyuk called on the Ministry of Defense and the General Staff to put troops on full combat alert Monday.
"This [situation in crisis-hit Donbas] demands the Defense Ministry and the General Staff to put Ukrainian armed forces on full combat alert," he told regional administration chiefs at a video conference.
He also called for equipping air-raid shelters.
Yatsenyuk urged the Ukrainian Ministry of Internal Affairs and the law enforcement in particular to fight terrorism and persecute everyone, who "trenches on the lives of Ukrainians and Ukrainian independence."
Ceasefire in Ukraine's conflict-torn Donbas region was stipulated by an agreement worked out by the leaders of Russia, France, Ukraine and Germany in the Belarusian capital, Minsk, and later signed by the envoys of the independence supporters and Kiev. The ceasefire came into force on February 15.
The new Minsk agreement came in the wake of simmering tensions in Donbas that continued despite a previous truce deal signed in September 2014.
