Azerbaijan says one of its generals and five other officers have been killed in a third day of fighting with Armenian forces on the countries’ border.
An Azeri private also died, bringing the official Azeri death toll so far to 11.
Azerbaijan says heavy fighting is continuing in Tovuz district, bordering on Tavush in north-eastern Armenia.
Armenia says two Armenian officers were killed. Nagorno-Karabakh, a disputed region to the south, remains tense.
Both sides accuse each other of shelling civilian areas on the border too.
Azerbaijan’s defence ministry said four Azeri troops had been killed in clashes on Sunday and Monday, involving tanks and artillery.
The conflict over Nagorno-Karabakh, controlled by ethnic Armenians, remains unresolved.
Azerbaijan’s military said it had destroyed an Armenian fortification and artillery and had inflicted casualties on “hundreds” of Armenian troops. Armenia denied suffering any casualties on that scale, but reported several wounded besides the two officers killed.
The two ex-Soviet republics in the Caucasus fought a bitter war in the 1990s, when Armenia backed the majority ethnic Armenians in Nagorno-Karabakh, a territory internationally recognised as part of Azerbaijan.
At an emergency meeting on Monday, Azerbaijani President Ilham Aliyev said: “Armenia’s political and military leadership will bear the entire responsibility for the provocation.”
Armenia, however, accused its neighbour of “using artillery in an attack aimed at capturing [Armenian] positions”.
On 6 July, President Aliyev said peace talks with Armenia to settle the long-standing Nagorno-Karabakh conflict had stalled.
He called recent talks between the countries’ foreign ministers “pointless”.
The Organisation for Security and Co-operation in Europe (OSCE) has long been trying to mediate a settlement of the conflict, which dates back to the 1990s.
The OSCE Minsk Group – diplomats from France, Russia and the US – is trying to build on a fragile ceasefire agreed in 1994.