The Armenian defense ministry announced Tuesday reaching a ceasefire agreement at the country's eastern border with Azerbaijan after about 3 days of border tension between the two countries.

"Under the mediation of the Russian side, a ceasefire agreement was reached at Armenia's eastern border from 18:30 (1430 GMT). The situation has relatively stabilized," the Armenian Defense ministry mentioned in a statement.

Clashes between the armies of the two countries have renewed on the border in the Nagorno-Karabakh region, since Sunday, and reached their climax on Tuesday.

The Armenian defense ministry stated that at least one of its soldiers died in the clashes, and Armenia had "lost control of two military positions."

It also reported that 12 Armenian servicemen were captured by the Azerbaijani military.

The two sides accused each other of initiating fighting along their shared border.

Armenia's defense ministry said Azerbaijani forces tried to "breakthrough" the border before being repelled.

In a security council meeting, Armenian Prime Minister Nikol Pashinyan accused Azerbaijan of "an aggression on Armenia's sovereign territory."

Russian Mediation

Armenia appealed to ally Russia for military support under the Collective Security Treaty Organisation pact (CSTO), which obliges Moscow to protect it in the event of a foreign invasion.

"Given that there was an attack on Armenia's sovereign territory, we appeal to the Russian Federation to protect Armenia's territorial integrity," said Security Council Secretary Armen Grigoryan.

In a statement, the Kremlin said Russian President Vladimir Putin discussed the situation with Pashinyan by phone and agreed to "continue contacts" on the matter. 

For his part, Russia's Defence Minister Sergei Shoigu held phone conversations with counterparts in Baku and Yerevan and pledged Moscow's help in easing tensions, the Interfax news agency reported.

Before the ceasefire was announced, the EU and the UN called on both sides to cease hostilities.

On Twitter, European Council President Charles Michel called for a "full ceasefire", as the UN urged Baku and Yerevan to "exercise restraint."

With @azpresident and @NikolPashinyan discussion in light of today’s developments.

Call for urgent de-escalation and full ceasefire.

Challenging situation in region - EU is committed to work with partners to overcome tensions for a prosperous and stable South Caucasus.

— Charles Michel (@eucopresident) November 16, 2021

Since last year's war, both Armenia and Azerbaijan have reported occasional exchanges of fire.