Azerbaijan's defence ministry said two servicemen were killed in an exchange of fire after Azerbaijani troops stopped a convoy it suspected of carrying weapons from the region's main town to outlying areas. It said the convoy had used an unauthorised road.
Armenia's foreign ministry said the convoy had been carrying documents and a service pistol and dismissed as "absurd" Azerbaijani allegations that weapons were being carried.
Armenian forces took control of Karabakh in a war that gripped the region as Soviet rule was collapsing in the early 1990s. Azerbaijan recaptured large swathes of territory in a six-week conflict in 2020 that ended with a truce and the dispatch of Russian peacekeepers, who remain in the region.
Azerbaijani President Ilham Aliyev and Armenian Prime Minister Nikol Pashinyan have met several times as part of efforts to resolve the conflict, but periodic violence has hurt peace efforts.
Azerbaijan said Armenia was to blame for the bloodshed and demanded an immediate withdrawal of Armenian troops from the territory.
The Armenian Foreign Ministry accused Azerbaijan of organizing an ambush that killed three police officers and denied arms smuggling claims as "disinformation."
Armenia said that Azeri forces shot at the police minivan as it was traveling south from Karabakh's main city of Khankendi to two villages near the Armenian border.
MNA/PR