An Azerbaijani soldier and an ethnic Armenian separatist fighter were reportedly killed in Azerbaijan's breakaway Nagorno-Karabakh region on May 17 in the fiercest fighting since a deadly battle killed dozens of people six weeks earlier.
The fresh fighting comes just one day after Azerbaijani President Ilham Aliyev and his Armenian counterpart Serzh Sarkisian agreed to respect a cease-fire and try to relaunch peace talks.
The agreement between the two leaders came after talks in Vienna brokered by U.S., Russian, and French mediators from the Minsk Group of the Organization for Security and Cooperation in Europe (OSCE) on May 16.
In addition to the cease-fire pledges by Aliyev and Sarkisian, the two presidents also agreed to increase the size of a cease-fire monitoring mission run by the (OSCE).
The current OSCE mission has only six observers on the ground.
EU foreign policy chief Federica Mogherini also met with Aliyev and Sarkisian on May 16 in Vienna.
Sarkisian said on May 17 that he was "generally satisfied" with the results of his meeting with Aliyev.
"Our goal is to solve the problems peacefully and through talks," Sarkisian said. "Warfare is, by far, not the best solution."
Meanwhile, the French Foreign Ministry said Azerbaijani Foreign Minister Elmar Mammadyarov will hold talks in Paris on May 19 with French Foreign Minister Jean-Marc Ayrault.
The meeting in Vienna on May 16 was the first face-to-face encounter between Aliyev and Sarkisian since a truce in early April halted four days of heavy fighting in the disputed region that killed at least 75 soldiers and several civilians.
That battle was the biggest outbreak of violence in and around Nagorno-Karabakh since a 1994 cease-fire was agreed after six years of fighting.
Both sides have blamed each other for initiating the fighting on May 17.
"Right after the Vienna talks, the Armenian side violated the cease-fire," Azerbaijan's Defense Ministry said in a statement on May 17.
For their part, military officials in the Armenia-backed Nagorno-Karabakh region accused Azerbaijani forces of shelling positions along the front line.
The separatists' self-styled government said one of its soldiers was killed "in the southern sector of the front."
Populated mainly by ethnic Armenians, the Nagorno-Karabakh region declared independence from Azerbaijan in the midst of a 1988-1994 war that killed an estimated 30,000 people and displaced hundreds of thousands.