Armenia has been transporting hundreds of militants from the Kurdish terror group the Kurdistan Workers' Party (PKK) and what Turkey believes is the group's Syrian branch, the Peoples' Protection Units (YPG), in its renewed fight against Azerbaijan over the Armenia-occupied region of Nagorno-Karabakh, Turkish security sources claim.
Around 300 militants belonging to the Kurdish groups were transported by Armenia from various countries in the Middle East and placed in Nagorno-Karabakh, where they have subsequently begun training Armenian militias in battle and guerrilla tactics against Azerbaijani forces over the past month or two, they added, speaking on condition of anonymity.
Turkish media reported them saying the transfer of militants was a result of a covert deal struck between Armenia and the PKK towards the end of July. The Armenian militias trained by the Kurdish militants are also reportedly those carrying out attacks on Azeri civilian settlements.
The militants reportedly make their way to Armenia through transit routes mainly in Iran and sometimes from northern Iraq.
Tensions between the two countries have spiralled in recent days due to renewed border clashes over the region occupied by Armenia since the weekend, in which both Azeri and Armenian forces have conducted attacks on military positions and civilian areas. The clashes prompted Azerbaijan to declare a state of war in some of its cities and areas near the border on Sunday.
Azeri forces have reportedly made numerous military advances over the past few days and recaptured multiple villages previously occupied by Armenia. According to the security sources, the capture of strategic hills has enabled Azeri forces to conquer areas in the region such as Seyid Ahmedli, Karakhanbeyli and Horadiz.
If Armenia's use of PKK militants is proven to be true, it would mean that the country is employing the expertise of a group designated as a terrorist organisation by the United States, European Union and Turkey.
It also follows on from claims that Azerbaijan had allowed Turkey to transport thousands of fighters from Syria and its rebel groups, which an aide to Azeri President Ilham Aliyev has denied.
Despite that denial, Turkey has declared its support for Azerbaijan and offered its assistance to its ally, calling on Armenia to withdraw from internationally-recognised Azeri territory of Nagorno-Karabakh which it occupied in 1991.
Following Turkey's support for Azerbaijan, the Armenian military yesterday claimed that Turkey used an F-16 fighter jet to shoot down a SU-25 fighter jet used by Armenian forces, without releasing any evidence of footage of the incident.
Turkey denied that it had shot down the jet, with Communications Director Fahrettin Altun telling the press in a statement "The claim that Turkey shot down an Armenian fighter jet is absolutely untrue. Armenia should withdraw from the territories under its occupation instead of resorting to cheap propaganda tricks."
The Azerbaijani Ministry of Defence also denied the allegation, saying in a statement it is "yet another fantasy of the Armenian military propaganda machine."