MOSCOW, May 22. /TASS/. One ceasefire violation was reported in Nagorno-Karabakh by Russian peacekeepers, the Russian defense ministry said in a regular bulletin on the activities of the peacekeeping contingent in the Nagorno-Karabakh conflict zone on Monday.

"A ceasefire violation was reported in the Martakert district. No casualties were reported," it said.

According to the ministry, a probe is underway. "Russian peacekeepers continue round-the-clock monitoring of the ceasefire at 30 observation posts," it added.