Azerbaijan and ethnic Armenian forces accused each other on Monday of launching new attacks in and around Nagorno-Karabakh, increasing strains on a two-day-old humanitarian ceasefire intended to end heavy fighting over the mountain enclave.
Russia, which brokered the ceasefire, appealed for both sides to respect it and Luxembourg reiterated European Union calls for Turkey, an ally of Azerbaijan, to do more to secure an end to hostilities that have killed hundreds of people.
The fighting, the deadliest over Nagorno-Karabakh in over 25 years, is being watched closely abroad partly because of its proximity to Azeri gas and oil pipelines and the risk of regional powers Turkey and Russia being dragged in.
Both Ankara and Moscow are under growing pressure to use their influence in the region to end the fighting.
The ceasefire is meant to allow ethnic Armenian forces and Azerbaijan to swap prisoners and bodies of people killed in two weeks of fighting over Nagorno-Karabakh, which is internationally recognised as part of Azerbaijan but governed and populated by ethnic Armenians.
But the ceasefire has frayed quickly. Azerbaijan said on Sunday it had launched air strikes against an Armenian regiment, following what it said was an Armenian rocket attack on an apartment building in the country's second biggest city of Ganja. Armenia denied carrying out such an attack..
On Monday, Azerbaijan's defence ministry said Armenian forces had tried to attack its positions around the Aghdere-Aghdam and Fizuli-Jabrail regions, and were shelling territories in the Goranboy and Terter regions inside Azerbaijan.
Nagorno-Karabakh said its forces had inflicted losses on Azeri forces and that large-scale military operations were continuing in the Hadrut area of the enclave.
Reuters could not independently verify the reports.
Kremlin spokesman Dmitry Peskov said Russia, which has a defence pact with Armenia, was monitoring the events and asked Azeri and ethnic Armenian forces to respect the ceasefire.
Turkey said in a statement its defence minister, Hulusi Akar, had told Russian Defence Minister Sergei Shoigu by telephone that Armenian forces must be removed from Azeri territory.
Turkey supports Azerbaijan's offensive to "retake its occupied lands", the statement said, adding that Baku "would not wait another 30 years" for a solution.
APPEALS TO TURKEY
Zohrab Mnatsakanyan, Armenia's foreign minister, met Russian Foreign Minister Sergei Lavrov in Moscow. He accused Azerbaijan of acting to expand Turkey's influence in the region and of using pro-Turkish mercenaries - charges both Ankara and Baku deny.
Accusing Azerbaijan of ceasefire violations, Mnatsakanyan said: "We want the ceasefire, we want verification mechanisms on the ground, which will indicate the perpetrator, which will demonstrate the party that is not faithful to this ceasefire."
Speaking before a meeting of EU foreign ministers, Luxembourg's foreign minister, Jean Asselborn, urged Turkey to do more to end the latest flare-up of the decades-old conflict.
"Turkey has not called for a truce yet, and I believe they are completely wrong with this position," Asselborn said.
"I think the message from Luxembourg will be a call on Turkey, a NATO member, to help arrange a ceasefire quickly."
While mediation has for years been led by France, Russia and the United States, Azeri President Ilham Aliyev repeated calls for Turkey to be involved.
"Even if many Western countries do not want to accept it, Turkey's word is big, it's fully independent," he said.
But Russia's Lavrov said there was no plan to change the talks format to include Turkey.
The fighting is the worst since a 1994 ceasefire ended a war over Nagorno-Karabakh that killed at least 30,000.
Azerbaijan said 41 Azeri civilians had been killed and 207 wounded since Sept. 27. It has not disclosed information about military casualties.
Nagorno-Karabakh said its military death toll since Sept 27 had reached 525, while at least 25 civilians had been killed.