Over the past 24 hours two soldiers have been killed in shelling and two more received fatal injuries during a mine explosion, the ministry said in a statement said.
Kiev forces accused Moscow-backed rebels of using weapons banned by peace agreements and firing at their positions nearly 30 times.
Rebels for their part accused the Ukrainian army of violating the truce more than 22 times.
The Organisation for Security and Cooperation in Europe (OSCE) said that on Wednesday its monitors recorded a sharp increase in ceasefire violations in Donetsk region compared with the previous day, including 520 explosions.
The OSCE Special Monitoring Mission to Ukraine also said it observed newly laid mines on both sides of the contact line.
Early on Wednesday a patrol was monitoring the security situation in the area of the Donetsk water filtration station when they heard the whistling sound of two bullets flying some 10-50 meters over their heads, the mission said.
The mission could not determine the direction of the fire, and departed.
The Ukraine conflict has claimed over 10,000 lives since April 2014 following Russia’s annexation of Crimea from Ukraine.
A series of truce agreements have helped reduce the fighting, although sporadic clashes continue and both military personnel and civilians face a constant threat from landmines.
Ukraine and its Western allies have accused Russia of funnelling troops and arms across the border. Moscow has denied the claims despite substantial evidence.--AFP