Mercenaries of Armenian origin from Syria have been identified among Armenia's casualties, Azerbaijan's Defense Ministry said Monday.
Defense Ministry spokesman Anar Eyvazov said in a statement that some of the dead bodies found among the casualties of the Armenian army were determined to be mercenaries of Armenian origin who came from Syria.
"The Armenian side hides this information from both the local and international community," Eyvazov said.
He added that the Azerbaijani army destroyed 24 tanks and armored vehicles, 15 OSA-type anti-aircraft systems and 18 unmanned aerial vehicles (UAV) belonging to the Armenian army.
Border clashes broke out early Sunday when Armenian forces targeted Azerbaijani civilian settlements and military positions, leading to casualties.
Azerbaijani President Ilham Aliyev on Monday signed a decree on partial military mobilization in the country.
Meanwhile, the country's parliament declared a state of war in some cities and regions following Armenia's border violations and attacks in the occupied Upper Karabakh region.
Relations between the two former Soviet nations have been tense since 1991, when the Armenian military occupied Upper Karabakh, also known as Nagorno-Karabakh, an internationally recognized territory of Azerbaijan.
Four UN Security Council and two UN General Assembly resolutions, as well as many international organizations, demand the withdrawal of the occupying forces.
The OSCE Minsk Group -- co-chaired by France, Russia and the US -- was formed in 1992 to find a peaceful solution to the conflict, but to no avail. A cease-fire, however, was agreed upon in 1994.
France, Russia and NATO, among others, have urged an immediate halt to clashes in the occupied region.
* Writing by Jeyhun Aliyev from Ankara