Karabakh’s Armenian-backed Defense Army said Azerbaijani forces backed by tanks, heavy artillery and helicopter gunships attacked its positions along the “line of contact” around the territory and shelled Karabakh villages and towns.
Details here [in Armenian]
The Karabakh Armenian army also claimed to have destroyed three Azerbaijani tanks and shot down two Azerbaijani military helicopters and as many unmanned aircraft.
Armenia’s Defense Ministry spoke of the most serious escalation of fighting in the Karabakh conflict zone since the 1994 truce that stopped a full-scale Armenian-Azerbaijani war.
“The enemy has been repelled along the entire Line of Contact, suffering numerous casualties as a result,” Defense Ministry Spokesperson Artsrun Hovhannisyan said.
Russian Defense Minister Sergey Shoigu has held negotiations with Armenian and Azerbaijani defense ministers over the phone and called for restoration of stability in the conflict zone.
Russian President Vladimir Putin has called on the two sides to "cease fire and exercise restraint"
MOSCOW / WASHINGTON / PARIS, 2 April, 2016 – The Co-Chairs of the OSCE Minsk Group (Ambassadors Igor Popov of the Russian Federation, James Warlick of the United States of America, and Pierre Andrieu of France) express grave concern over the reported large-scale ceasefire violations that are taking place along the Line of Contact in the Nagorno-Karabakh conflict zone. We strongly condemn the use of force and regret the senseless loss of life, including civilians.
The Co-Chairs call upon the sides to stop shooting and take all necessary measures to stabilize the situation on the ground. They reiterate that there is no alternative to a peaceful negotiated solution of the conflict and that war is not an option.
"Gravely concerned by cease fire violations in Nagorno-Karabakh. The sides must stop shooting and stabilise the situation," NATO Deputy Assistant Secretary General for Political Affairs. Special Rep for Caucasus and Central Asia.