Russian investigators have re-qualified the criminal case on a Russian military helicopter, which was shot down by Azerbaijan above the Azerbaijani-Armenian border, under a more severe article of the Russian Criminal Code, Interfax reported.

"The criminal case, which was originally instituted along the lines of the article on ‘Flights violation that resulted in death by negligence,' has been re-qualified under a more severe article: 'Premeditated murder of two or more persons,'" the source of the agency said.

He added that if in the first case up to 7 years of imprisonment is envisaged, then in the second case—up to life imprisonment. Moreover, this decision was made as a result of the investigation being carried out within the framework of the said criminal case.

The source, however, found it difficult to say how long this investigation will continue. "There are some difficulties in this matter due to the fact that the suspects are in the territory of another state," the source said.

According to him, this investigation is being conducted by Russian military investigators who are stationed in Gyumri, Armenia.

On November 9, a Russian military helicopter, which was accompanying a convoy of the 102nd Russian Military Base in Gyumri was shot down in Armenia’s airspace. Two Russian servicemen were killed and another was injured. The helicopter was shot down more than 100 km away from the Nagorno-Karabakh (Artsakh) conflict zone. Azerbaijan claimed responsibility for the incident, saying it had "mistakenly" shot down the helicopter, apologized, and expressed readiness to pay compensation to Russia. And in the evening of the same day, a statement on a ceasefire in the Karabakh conflict zone was signed between the leaders of Armenia, Russia, and Azerbaijan.