Deadly clashes between Azerbaijani and Armenian forces over the Nagorny Karabakh region continued for a third day on Monday despite international pressure to halt the worst fighting in decades over the disputed territory.
Azerbaijan said three of its troops were killed overnight when Armenian forces shelled its positions using mortars and grenade launchers, taking the overall death toll in the latest surge of violence to at least 36.
"In the event of continued Armenian provocations, we will launch a full-scale operation along the entire front line, using all kinds of weapons," Azerbaijan's defense ministry spokesman Vagif Dargahly told journalists.
The separatist authorities in Karabakh said that Azeri troops "intensified shelling of the Karabakh army positions on Monday morning, using 152-millimeter mortars, rocket-propelled artillery and tanks".
The fresh outbreak of fighting over the region - which was seized by Armenian rebels from Azerbaijan in a war that ended with an inconclusive truce in 1994 - erupted on Friday night with the two sides accusing each other of attacking with heavy weaponry.
Azerbaijan claimed to have snatched several strategic positions inside the Armenian-controlled territory in what would be the first change in the front line since the cease-fire 22 years ago.
In the Armenian capital of Yerevan, defense ministry spokesman Artsrun Hovhannisyan said on Monday that Karabakh forces had "seriously advanced at certain sectors of the front line and took up new positions".
The report was dismissed as "untrue" by Azerbaijan.
Russia and the West have called for a cease-fire, with Russian President Vladimir Putin pushing for an immediate end to the fighting, and Moscow's diplomats and military pressuring both sides.
At least 18 Armenians, 15 Azeri troops and three civilians were reported killed, and one of Azerbaijan's attack helicopters was shot down.
On Sunday, Azerbaijan said it had decided to "unilaterally cease hostilities" and pledged to "reinforce" the positions it claimed to have captured.
The authorities in Karabakh which claims independence, said they were willing to discuss a cease-fire but only if it would help them regain their territory.