BAKU, July 13 (Xinhua) -- Four Azerbaijani soldiers were killed in a fresh wave of clashes on the Azerbaijan-Armenia border.
Three soldiers were killed on Sunday and one on Monday in artillery fire near the northern Tavush region, Azerbaijan's Ministry of Defense said on Monday.
According to the Armenian Defense Ministry, at least two Armenian police officers were wounded in the clashes.
The two countries have traded accusations over which side started the fighting and violated the ceasefire.
Both countries said the situation is under their control.
The deadly clashes were reportedly erupted on Sunday in the Tavush region between the two countries.
As a member of the OSCE (Organization for Security and Co-operation in Europe) Minsk Group co-chairs, Russia's Foreign Ministry on Monday expressed concern in a statement over the escalation of the clashes and urged the two countries to exercise restraint.
Armenia and Azerbaijan have been at loggerheads over the mountainous region of Nagorno-Karabakh since 1988. Peace talks have been held since 1994 when a ceasefire was reached, but there have been occasional minor clashes along the borders.