Armenians have protested after reports as many as 100 soldiers were seized in a raid by Azerbaijani forces in Armenian-controlled Nagorno-Karabakh.
A six-week war that claimed at least 5,000 servicemen’s lives was brought to an end last month, with Azerbaijani forces taking some territory.
On Tuesday night, Nagorno-Karabakh’s defence ministry said contact had been lost with a number of military posts.
There has been no comment so far on the soldiers’ reported capture from Azerbaijan’s defence ministry.
While Nagorno-Karabakh is recognised internationally as part of Azerbaijan, it has been run by ethnic Armenians since an earlier war came to an end in 1994. Azerbaijan regained some of its territory in the recent six-week conflict, and the latest flare-up appears to have happened in one such area.
Anger spread as videos emerged on social media in Azerbaijan and Nagorno-Karabakh human rights ombudsman Artak Beglaryan said it was highly likely that captive Armenian soldiers were featured in the footage. He put the number missing at around 60.
Families of the missing men blocked a main road demanding to know more details and protesters marched on the defence ministry in the Armenian capital Yerevan.
The exact number of captured soldiers is unclear but reports range from 60 to as many as 160, seized as part of an Azerbaijani “anti-terror” operation. Several videos posted online appeared to show captured soldiers. The defence ministry in Azerbaijan has refused to discuss the matter with the BBC.
The operation in southern Nagorno-Karabakh began at the end of last week. Armenia accused Azerbaijan of breaking the November peace deal by attacking the two villages called Hin Tagher (Kohne Taglar in Azerbaijani) and Khtsaberd (Calakkala).
Azerbaijan says the two villages fall under its control under the peace deal and that it launched the offensive to tackle Armenian servicemen who had refused to leave the area after the truce. Four Azerbaijani soldiers were killed at the weekend, the first casualties since the war came to an end on 10 November.
On Tuesday evening, Nagorno-Karabakh’s defence ministry said it had lost communication with personnel of a number of army positions around the two villages.
Although 2,000 Russian peacekeepers have been deployed between the two sides, Armenian reports said they were not covering the area where clashes had taken place.
When Russia’s defence ministry published a map extending its peacekeepers’ deployment to cover the area, Azerbaijan objected.
Since the war ended in November, Armenia has handed over three areas lost in the war to Azerbaijan under a peace deal.
The two sides also began exchanging prisoners of war this week, with Armenian Prime Minister Nikol Pashinyan promising that 44 servicemen would return home.
In a separate development, Azerbaijan said it had charged two of its soldiers with mutilating the bodies of Armenian soldiers during the war.