HEREVAN. Tensions are rising again in Nagorno-Karabakh as three soldiers were killed early Thursday and Azerbaijan announced it had seized a number of strategically important heights in the disputed region. The resumption of the crisis prompted an immediate international backlash, with Russia accusing Baku of violating a fragile ceasefire and the European Union calling for an immediate ceasefire.

Baku claims that Armenian forces attacked Azerbaijani positions in the Lachin region, where Russian troops are stationed.

Armenia and Azerbaijan fought twice, in 2020 and in the 1990s, over the Azerbaijani-controlled but predominantly Armenian region of Nagorno-Karabakh. Armenia has surrendered part of the territory it has controlled for decades, and Russia has sent 2,000 troops to oversee the ceasefire. On Wednesday, Baku reported the death of one soldier, while Yerevan announced the death of two of its soldiers and more than ten wounded. Baku claims that Armenian forces attacked Azerbaijani positions in the Lachin region, where Russian peacekeepers are deployed. The Azerbaijani headquarters issued an order to carry out an operation code-named “Revenge” with the capture of strategic heights, and the Baku government decided to order a partial mobilization of reserves. Armenia, for its part, accuses Azerbaijan of trying to create a fait accompli in its favor in the Lachin “corridor” connecting Armenia with Karabakh.