Deadly border clashes between Armenia and Azerbaijan entered a second day, as the European Union and Russia urged restraint.
Azerbaijan’s Defense Ministry said three of its soldiers were killed on July 12 and one on July 13, adding that both sides used artillery, mortars, and tanks in the northern area of their border.
The Armenian Foreign Ministry said the artillery fire from Azerbaijan "receded" later on July 13, claiming Yerevan was "fully controlling" the situation.
"Armenia's political and military leadership will bear the entire responsibility for the provocation," Aliyev said on July 13.
Armenian Prime Minister Nikol Pashinian accused Azerbaijan of "provocations" that would "not go unanswered."
In a statement on July 13, the EU urged both sides to "stop the armed confrontation, refrain from action and rhetoric that provoke tension, and undertake immediate measures to prevent further escalation."
Russian Foreign Minister Sergei Lavrov held phone conversations with his Armenian and Azerbaijani counterparts, urging de-escalation.
Russia’s Foreign Ministry expressed "serious concerns" over the clashes, which it said "endangers the region's stability," urging the countries to "show restraint."
The two neighbors have been locked in a conflict over Azerbaijan's breakaway region of Nagorno-Karabakh for years.
But the clashes over the past two days were far from Nagorno-Karabakh and directly between the two nations, which occurs rarely.
The clashes came days after Aliyev raised the possibility of a new war with Armenia and denounced stalled peace talks.
On July 7, Aliyev threatened to withdraw from negotiations "if they yield no results." He did not provide further details.
Mainly Armenian populated Nagorno-Karabakh declared independence from Azerbaijan amid a 1988-94 war that claimed an estimated 30,000 lives and displaced hundreds of thousands of people.
Since 1994, it has been under the control of ethnic-Armenian forces that Azerbaijan says include troops supplied by Armenia. The region's claim to independence has not been recognized by any country.
Negotiations involving the Minsk Group of the Organization for Security and Cooperation in Europe (OSCE), co-chaired by Russia, the United States, and France, helped forge a cease-fire in the region, which is not always honored, but have failed to produce a lasting settlement of the conflict.
Deadly Clashes Along Azerbaijan-Armenia Border Enter Second Day Amid Calls For Restraint