The OSCE Minsk Group issued the following statement:

The Minsk Group Co-Chairs (Ambassadors Igor Popov of the Russian Federation, James Warlick of the United States, and Pierre Andrieu of France) express our very serious concern about the downing of a helicopter near the Line of Contact and the recent violence. We regret the loss of life and express our condolences to the families. 

The Co-Chairs are deeply worried by the events that prompted this drastic incident, the first of its kind since the ceasefire agreement was reached.  We strongly appeal to the sides to avoid steps that would escalate tension along the Line of Contact and Armenia-Azerbaijan border.  The region cannot afford another round of violence like we witnessed this summer.  Today's events remind us of the volatility of the Nagorno-Karabakh conflict and the urgency to intensify efforts to find a lasting settlement. We remain resolved to assist the sides in any way possible.

We remind the Presidents of Armenia and Azerbaijan of their responsibilities to respect the ceasefire and honour the commitments they made in Sochi, Newport, and Paris to find a peaceful resolution to the conflict.  We also encourage them to adopt confidence-building measures now that would increase transparency along the Line of Contact and the Armenia-Azerbaijan border, and reduce the likelihood of events like today's incident.