Four ethnic Armenian soldiers were killed by artillery and gunfire from Azerbaijani forces on September 25 near the breakaway Nagorno-Karabakh region, Nagorno-Karabakh's Defense Ministry said.
The latest clash comes one day after Armenia said three civiliian women were killed by Azerbaijani fire in Armenia's Tavush region.
Azerbaijan did not immediately comment on the latest clash, but it has accused Armenia of "turning civilians into a target by deliberately stationing its firing positions in and around civilian facilities to shell positions of the Azerbaijani armed forces."
Yerevan and Baku are locked in a decades-long conflict over Nagorno-Karabakh, an ethnic Armenian enclave in Azerbaijan, which is claimed by both ex-Soviet nations.
The two sides regularly exchange fire along their border and across Karabakh's volatile front line.
On September 25, international mediators of the Organization for Security and Cooperation in Europe, which has sought to mediate peace in Karabakh, expressed "serious concerns about Armenian and Azerbaijani forces using mortars and heavy weapons in and around civilian areas."
"The use of such weapons represents an unacceptable escalation in the conflict," said the Minsk Group of mediators co-chaired by France, Russia, and the United States.