Pro-Russian rebels have removed grad rockets and artillery banned under the eastern Ukraine ceasefire agreement from storage units in the contested region of Donbas, claims a report by the Organization for Security and Cooperation in Europe, the group charged with overseeing the ceasefire. While the OSCE Special Monitoring Mission is unsure where the weapons have been moved, their removal comes at a time of heightened tension between pro-Russian rebels and Ukrainian government troops that has seen fighting and the death toll increase across the region.

“At one location, six Grad systems were missing,” noted the report from Wednesday. “The [Donetsk People's Republic] commander told the SMM that the weapons were removed for training purposes. At a second site, four of six self-propelled Howitzers (2S1, 152 mm caliber) were removed -- according to persons at the site -- for training.”

The ban on the use of heavy weapons, specifically Grad rockets, was agreed to by Russian separatists and the Ukrainian government under the Minsk II talks on Feb. 12. However, few days have seen peace in the region over the last three months, and for the first time since the ceasefire came into force, the use of Grad rockets was recorded by the OSCE last week.   

The Grad rocket system is a Russian-built weapon that can fire up to 40 rockets at once, causing high-level, indiscriminate damage. A batch of rockets fired by pro-Russian separatists hit a bus in a small Ukrainian town earlier this year. The rockets have killed hundreds of Ukrainian troops since the war began in March 2014. 

The observers that noticed the absent weapons also attempted to visit Ukrainian heavy-weapon storage sites on the same day, but were told on two occasions that access was denied as the commander of the compound was not present. Ukraine also possesses Grad rocket systems. 

While both sides have promised that heavy weaponry has been withdrawn from the front lines, as specified in the ceasefire agreement, the OSCE has recorded the movement of such weapons in front-line areas.

Wednesday’s report also noted that 10 rebel tanks were seen around the region.