© Reuters / Aziz Karimov
A burnt car, which was hit by shelling during a military conflict over the breakaway region of Nagorno-Karabakh, in the town of Barda, Azerbaijan.
Armenia and Azerbaijan have again accused one another of shelling civilians, as fighting over the disputed Nagorno-Karabakh region continues after the failure of the US-brokered truce earlier this week.

Azerbaijan said that Armenian forces have shelled the cities of Tartar and Barda. The strikes on the latter are said to have killed 21 civilians and left dozens of people injured. The attack was allegedly carried out using Smerch multiple rocket launchers.

Azerbaijani officials have invited foreign diplomats and human rights groups to visit the city and see the aftermath of the shelling for themselves. They also posted photos of destruction and body bags lying on the ground on social media.

Armenia's Defense Ministry has denied targeting Barda and labelled Baku's claims "groundless and deceitful."

The Armenia-backed forces in Nagorno-Karabakh, meanwhile, have accused the Azerbaijani military of shelling two of the largest cities in the self-proclaimed republic.

In the capital, Stepanakert, a maternity hospital was hit, but there were no reports of casualties; while in Shusha one person was killed and two others injured, they said.

Nagorno-Karabakh's human rights ombudsman has shared pictures on Twitter showing the destruction caused by the alleged attack. Baku, however, insisted the Armenian statements were nothing but "disinformation."

Besides mutual accusations of shelling, there were also reports of resumed scuffles between the two sides along the contact line.

Baku is being backed by Turkey during this latest flare-up, with reports claiming that Syrian militants have been deployed to fight the Armenian forces and Turkish F-16s used in the raids. The mainly Armenian-populated region of Nagorno-Karabakh, which is internationally recognized as part of Azerbaijan, unilaterally declared independence from Baku in the early 1990s and has since been backed by Armenia. Azerbaijani authorities, who consider the area illegally occupied by Yerevan, have vowed to regain control of it.

The truce, which was brokered by Washington but failed on Monday, was already the third attempt to bring the violence to a halt in Nagorno-Karabakh, following two previous attempts backed by Russia. Both sides of the conflict refuse to lay down their arms, each accusing the other of unwillingness to search for compromise or make any concessions.