New tensions erupted over Nagorno-Karabakh on Wednesday as three soldiers were killed and Azerbaijan said it had taken control of several strategic heights in the disputed region.

Armenia and Azerbaijan fought two conflicts over Azerbaijan's Armenian-populated area of Nagorno-Karabakh, one in 2020 and one in the 1990s.

Six weeks of violence in the autumn of 2020 claimed over 6,500 lives and ended with a ceasefire accord sponsored by Russia.

Russia sent 2,000 peacekeepers to monitor the truce, but tensions remain despite a ceasefire deal.

The Azerbaijani Defense Ministry claimed on Wednesday that Karabakh troops attacked Azerbaijani army posts in the district of Lachin, which is overseen by the Russian peacekeeping force, killing an Azerbaijani conscript.

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According to Baku's Foreign Ministry, the "bloody episode" indicated that Armenia violated the ceasefire agreement.

"All responsibility for the incident in Azerbaijan lies with the military and political leadership of Armenia, which has not yet withdrawn its illegal armed formations from the territory of the neighboring state," the Foreign Ministry said in a statement.

The army of the breakaway statelet accused Azerbaijan of breaking a ceasefire and murdering two troops while injuring 14 others.

Karabakh declared a "partial mobilization", the army said in a statement, adding that the situation was "relatively stable" Wednesday evening.

"Measures are being taken together with Russian peacekeepers to stabilize the situation," the Karabakh army said.

Azerbaijani Military captures several heights in Karabakh

The Azerbaijani troops took multiple heights in Nagorno-Karabakh on Wednesday, according to the Defense Ministry's press office.

The Ministry claims that Armenian forces engaged in sabotage against the Azerbaijani military, in breach of trilateral agreements signed by Baku, Yerevan, and Moscow.

"As a result of the response operation carried out by the units of the Azerbaijan military, several heights in Karabakh were taken under control," the office said.

Russian MoD: Azerbaijan breached ceasefire in Karabakh

On its part, the Russian Defense Ministry stated in a report on the activities of Russian peacekeepers in the Nagorno-Karabakh conflict zone that the Azerbaijani Armed Forces violated the ceasefire in the region of the height of Sarybaba.

"The situation in the zone of responsibility of the contingent is aggravated. In the area of ​​​​the height of Sarybaba, the ceasefire regime was breached by the armed forces of Azerbaijan. The command of the Russian peacekeeping contingent, together with representatives of the Azerbaijani and Armenian sides, is taking measures to stabilize the situation," the Ministry said.