UN and EU leaders have urged Armenia and Azerbaijan to de-escalate tensions after Baku accused Yerevan of provoking fire across the border.
The United Nations has urged Armenia and Azerbaijan to "exercise restraint" after border clashes, which come a year after the countries fought a war over the occupied Karabakh region.
At the UN on Tuesday, deputy spokesperson Farhan Haq said, "We urge all sides to exercise restraint ... and address any related concerns peacefully through dialogue."
"We want to avoid any return to the sort of escalation we had earlier," Haq added.
EU chief Charles Michel on Tuesday urged the leaders of Armenia and Azerbaijan to call a "full ceasefire".
Michel, the president of the European Council, said he had spoken to President Ilham Aliyev of Azerbaijan and Prime Minister Nikol Pashinyan of Armenia.
Michel did not apportion blame for the "challenging situation in the region", but demanded an "urgent de-escalation and full ceasefire."
"EU is committed to work with partners to overcome tensions for a prosperous and stable South Caucasus," he tweeted.
Turkey's Defence Minister Hulusi Akar discussed the developments on the border during a telephone meeting with his Azerbaijani counterpart Zakir Hasanov and reiterated Ankara’s support for Baku.
Armenia said on Tuesday that its side suffered fatalities and lost control of two military positions "following an attack by Azerbaijani forces."
Azerbaijan accused Armenia of provoking the clash, and said two of its own soldiers were wounded.
The Azerbaijani army said it immediately carried out an emergency operation, adding that the movement of the Armenian forces was blocked, while its forces and means were damaged.
During the six-week war last year, Azerbaijan retook several cities and 300 settlements and villages. The conflict, which left more than 6,500 dead, ended in November 2020 in a Russian-brokered deal that saw Armenia cede swathes of territory it had occupied for decades.