At least 21 civilians killed, 70 others wounded in the attack Baku blames on Yerevan. A ceasefire implemented earlier this week has failed to take hold as both sides accuse each other of violations.
Azerbaijan has said an Armenian missile strike on its Barda district near the Nagorno-Karabakh frontline killed 21 civilians and wounded 70 others.
It would be the deadliest reported attack on civilians since new fighting over the disputed region broke out a month ago. Yerevan has denied carrying out an attack.
The worst fighting in the region for nearly 30 years has raised fears of a wider war that also poses a threat to pipelines carrying oil and gas from Azerbaijan to world markets.
Azerbaijani presidential aide Hikmet Hajiyev said Armenian forces had fired Smerch missiles on Barda.
While security measures were tightened against a possible second attack in the city, many businesses, including all cafes and restaurants, were closed, reports said.
"There can be no justification for such attacks," the UN said in a statement.
"We strongly condemn all attacks on populated areas impacted by the conflict, including the strikes on the city of Barda, which reportedly killed and wounded many," it said, adding both sides must "immediately implement" the humanitarian ceasefire.
In Barda number of killed more than 20. Number of wounded reached 60. Armenia used cluster munitions to inflict excessive casualties among civilians. It is policy of state terror by Armenia. Delibarately city center of Barda was targeted. pic.twitter.com/SVTgzWpodz— Hikmet Hajiyev (@HikmetHajiyev) October 28, 2020
Armenian-backed officials in Nagorno-Karabakh said Azerbaijani shells had fallen on the enclave's two largest cities, killing one person.
Both sides denied each other's claims.
"The statement of the ministry of defence of Azerbaijan that the Armed Forces of Armenia allegedly hit the town of Barda with Smerch is groundless and false," Armenian Defence Ministry spokesperson Shushan Stepanyan said on Facebook.
Nagorno-Karabakh is internationally recognised as part of Azerbaijan but is under the control of ethnic Armenians since the 1991-94 war in the region. About 30,000 people were killed in the conflict which followed the fall of the Soviet Union.
Turkish and Azerbaijani foreign ministers on Wednesday discussed the latest developments in the occupied-Nagorno-Karabakh region, according to diplomatic sources.
Mevlut Cavusoglu and his Azerbaijani counterpart Jeyhun Bayramov spoke over the phone.
This came after a Washington-brokered truce last weekend proved short-lived after Azerbaijan said Yerevan breached the new humanitarian ceasefire.
The recent US-brokered temporary humanitarian truce was announced on Sunday and took effect 0400 GMT on Monday.
Baku said on Monday that Armenian forces continued to attack Azerbaijani civilian settlements and military units.
On Tuesday, four civilians including a toddler were reported dead in an Armenian missile strike on a village in Barda, but Yerevan denied carrying out that attack as well.
"In violation of humanitarian ceasefire and in order to compensate their sustained military losses, Armenia resorts to war crimes of killing civilians," Hajiyev said in English on Twitter.
According to ANAMA Armenia used cluster Smerch missile against civilians in Barda. Use of cluster weapons against civilians is forbidden. 4 civilians, including 2 years old baby girl killed. 13 civilians wounded. Because of #cluster bomblets number of casualties quite big. pic.twitter.com/Uyg1ri2uyo— Hikmet Hajiyev (@HikmetHajiyev) October 27, 2020
Harutyunyan hit by UAV strike
The so-called defence minister of Armenian-occupied Nagorno-Karabakh was reportedly relieved of duties after being "wounded" in combat on Tuesday.
It is also reported by local media that Jalal Harutyunyan, accused by Baku of committing war crimes in the occupied-Karabakh, was successfully targeted and hit by a UAV strike.
More than 100 civilians from both sides have been killed since fresh clashes erupted on September 27 between Azerbaijani and Armenian forces over Nagorno-Karabakh.
Both sides have accused each other of failing to respect ceasefire agreements mediated by Russia, France, and the United States.
Several non-binding UN resolutions have acknowledged Nagorno-Karabakh as Azerbaijan's land and Baku has rejected any solution that would leave Armenians in control of the enclave.
The OSCE Minsk Group, formed to mediate the conflict and led by France, Russia and the United States, is scheduled to meet the Armenian and Azerbaijani foreign ministers in Geneva on Thursday.