TBILISI: Russia expressed concern on Thursday over escalating tensions between Armenia and Azerbaijan as a key road linking Armenia to the disputed Nagorno-Karabakh enclave remained blocked for the fourth day.

The two countries have fought repeated wars over Nagorno-Karabakh - internationally recognised as part of Azerbaijan but home to about 120,000 ethnic Armenians - since the 1991 collapse of the Soviet Union. As recently as September, more than 200 soldiers were killed in a flare-up of fighting.

A group of Azerbaijanis claiming to be environmental activists blocked the Lachin corridor, the only land route for people, goods, food and medical supplies to reach Nagorno-Karabakh from Armenia across Azerbaijani territory, at the start of this week.

Reuters video showed a crowd of people, many carrying Azerbaijani flags, blocking the road on Thursday in a peaceful standoff with Russian troops from a 5,000-strong mission deployed to the region after the last round of war in 2020.

Armenian Prime Minister Nikol Pashinyan said the closure of the passage was a “gross violation” of that year’s peace agreement between Baku and Yerevan and that the population of the enclave had been made into hostages.

Armenia says the protesters have been dispatched by the Azerbaijani government in an attempt to block Armenia’s access to the region.