Azerbaijan and Armenia reported casualties of Nagorno-Karabakh, while accusing each other of violating a complete Russia-brokered ceasefire in the disputed region.
Sunday's accusations came a month after the two sides agreed to the ceasefire in their latest round of armed-conflict in the region that erupted in September, reports Xinhua news agency.
Azerbaijan's Defence Ministry and the State Security Service said in a joint-statement that Armenian servicemen attacked Azerbaijani troops twice in Hadrut between November 26 and December 8, resulting in the deaths of four personnel, along with three injuries including one civilian, reports Xinhua news agency.
Meanwhile, the Foreign Ministry of Armenia said on Sunday that the Azerbaijani special forces' attack in Hadrut on December 11 injured six Armenian servicemen.
The Russian Defence Ministry reported the violation of the ceasefire a day earlier, but did not specify which side opened fire first.
Armed clashes between the two South Caucasus countries in Nagorno-Karabakh came to a halt on November 10 after Azerbaijani President Ilham Aliyev, Armenian Prime Minister Nikol Pashinyan and Russian President Vladimir Putin issued a joint statement agreeing to the complete ceasefire.
The agreement led to the deployment of thousands of Russian peacekeepers to the enclave and border regions, after six weeks of escalating conflict over Nagorno-Karabkh, which reportedly left thousands dead and more displaced.
This is the fourth ceasefire since last month.