MOSCOW, November 13. /TASS/. The destruction of a helicopter in the Nagorno-Karabakh conflict zone provokes further escalation of tensions in the region, the Collective Security Treaty Organization (CSTO) Secretariat said on Thursday.

“On November 12, Azerbaijan destroyed a helicopter, which conducted a training flight, in the Nagorno-Karabakh conflict area. The crewmembers died. This dangerous incident provokes further escalation of tensions in the region and heightens anxiety,” the CSTO said.

“The threat of the new escalation of tensions emerged. The situation in the South Caucasus is becoming more and more acute,” it said.

Throughout the year, armed incidents have become more frequent on the line of contact between Azerbaijani and Karabakh troops. “Only over the three months, the ceasefire agreements have been violated about 1,500 times,” the CSTO said.

CSTO Secretary-General Nikolay Bordyuzha said, “We’re convinced that it is necessary to prevent the dangerous development of the situation. The key task to prevent such developments is to give up the use of force, strictly comply with the ceasefire agreements and prevent provocative actions. It is important to continue the negotiating process on the settlement of the Nagorno-Karabakh problem.”

On Wednesday, the OSCE Minsk Group, including Russia, France and the US, called on Azerbaijan and Armenia to take urgent steps towards preventing the escalation of tensions in the region.

The Nagorno-Karabakh conflict began on February 22, 1988. On November 29, 1989 direct rule in Nagorno-Karabakh was ended and Azerbaijan regained control of the region. However, later a joint session of the Armenian parliament and the top legislative body of Nagorno-Karabakh proclaimed the unification of Nagorno-Karabakh with Armenia.

The struggle over Nagorno-Karabakh escalated after both Armenia and Azerbaijan obtained independence from the Soviet Union in 1991. By the end of 1993, the conflict had caused thousands of casualties and forced hundreds of thousands on both sides to flee. An unofficial ceasefire was reached on May 12, 1994.