The OSCE Mink Group Co-Chairs and the European Union on Friday added their voices to the growing international concern over the deepening crisis along Armenia’s border, which was breached on May 12 with Azerbaijani forces advancing into Armenia’s Syunik and Gegharkuik provinces.

On Thursday, six Armenian soldiers were captured by Azerbaijani forces in Gegharkunik and despite wide-spread international calls for Azerbaijan to release them and all prisoners of war, Baku has refused to do so. Azerbaijani forces also shot and killed an Armenian soldier, Gevorg Khurshudyan on Tuesday in the same area.

The OSCE Minsk Group Co-Chairs, Igor Popov of Russia, Stephane Visconti of France, and Andrew Schofer of the United States, in a statement released on Friday said they held talks with International Committee of the Red Cross (ICRC) President Peter Maurer and UN High Commissioner of Refugees Filipino Grandi in Geneva on May 27 and 28 with the Personal Representative of the OSCE Chairperson in Office Andrzej Kasprzyk also in attendance.

“The Co-Chairs take note of the reported detention of six Armenian soldiers on May 27 and call for the release of all prisoners of war and other detainees on an all for all basis. The Co-Chairs underscore the obligation to treat detainees in accordance with international humanitarian law. The Co-Chairs strongly urge the sides to lift all restrictions on humanitarian access to Nagorno-Karabakh immediately, and call on the sides to implement in full the commitments they undertook under the November 9 ceasefire declaration,” said the statement.

“The Co-Chairs also note with concern several recent reports of incidents on the non-demarcated Armenia-Azerbaijan border. The use or threat of force to resolve border disputes is not acceptable. We call on both sides to take immediate steps, including the relocation of troops, to de-escalate the situation and to begin negotiations to delimitate and demarcate the border peacefully. The Co-Chairs stand ready to assist in facilitating this process,” added the Co-Chairs.

“Having in mind the terms of their OSCE mandate and the aspirations of all the people of the region for a stable, peaceful, and prosperous future, the Co-Chairs again call on the sides to reengage under their auspices at the earliest opportunity,” added the statement.

Recent developments on the Armenia-Azerbaijan border are both dangerous and worrying, Peter Stano, lead Spokesperson for Foreign Affairs and Security Policy, said in a statement, adding that immediate de-escalation is needed.

“The European Union urges both sides to refrain from any further military deployment and actions. All forces should pull back to positions held before 12 May and both sides should engage in negotiations on border delimitation and demarcation. We continue to call on Azerbaijan to release all prisoners of war and detainees without delay. We welcome all efforts aimed at decreasing tensions, including proposals for a possible international observation mission,” said Stano.

“The EU is ready to provide expertise and help on border delimitation and demarcation, as well as to support much needed confidence building measures, in order to move towards sustainable peace and prosperity for the South Caucasus,” he concluded.

Also on Friday, the EU High Representative for Foreign Affairs and Security Policy/Vice-President of the Commission Josep Borrell has said that a group of European ministers would visit the Caucasus to assess the situation there first hand.

“A group of [European Union] Ministers will visit the three South Caucasus countries on my behalf to show our readiness to further engage in the region,” Borrell said at the informal meeting of EU Foreign Affairs Ministers in Lisbon, Portugal.