Armenia-backed separatists said on March 1 that one of their soldiers was killed in clashes with Azerbaijani forces along the boundary of the breakaway Nagorno-Karabakh region.
Nagorno-Karabakh's self-declared defense ministry said Azerbaijani forces had been violating cease-fire agreements all day.
The Azerbaijani Defense Ministry said that their forces detected and destroyed some Armenian combat vehicles during a maneuver.
"The Armenian armed forces have been suffering losses, mainly mercenaries of Armenian origin," the ministry said in a statement.
Five Azerbaijani soldiers were killed in clashes with Armenia-backed separatists last week and both sides have been accusing each other of an attempted incursion.
Armenia-backed separatists seized control of Nagorno-Karabakh, which is mainly populated by Armenians, during a war in the early 1990s that killed some 30,000 people.
A cease-fire was agreed in 1994 but it has not always held, and diplomatic efforts to permanently settle the conflict have brought little progress.
Based on reporting by Reuters and Interfax