Armenia said a woman and a child were killed in the area by shelling from Azerbaijani forces, while Azerbaijan’s president said his military had suffered losses.
Armenia also claimed that two Azerbaijani helicopters were shot down and three Azerbaijani tanks were hit by artillery, but Azerbaijan’s defence ministry rejected that claim.
Azerbaijan’s forces destroy an Armenian anti-aircraft system (Armenian Defence Ministry via AP)
Heavy fighting broke out in the morning in the region that lies within Azerbaijan but has been under the control of ethnic Armenian forces backed by Armenia since 1994 at the end of a separatist war.
It was not immediately clear what had sparked the fighting, the heaviest since clashes in July killed 16 people from both sides.
Nagorno-Karabakh authorities reported that shelling hit the region’s capital of Stepanakert and the towns of Martakert and Martuni.
Armenian Defence Ministry spokesman Artsrun Hovhannisyan also said Azerbaijani shelling hit within Armenian territory near the town of Vardenis.
Armenian human rights ombudsman Arman Tatoyan said a woman and a child were killed and two civilians wounded in the Martuni region.
Another Armenian Defence Ministry spokeswoman, Shushan Stepanyan, said “the Armenian side” shot down two helicopters and hit three tanks.
Azerbaijan’s president Ilham Aliyev said in a televised address to the nation that “there are losses among the Azerbaijani forces and the civilian population as a result of the Armenian bombardment” but did not give further details.
Azerbaijani president Ilham Aliyev addresses the nation (Azerbaijani Presidential Press Office via AP)
He also claimed that “many units of the enemy’s military equipment have been destroyed”.
Russian foreign minister Sergey Lavrov “is conducting intensive contacts in order to induce the parties to cease fire and start negotiations to stabilise the situation,” ministry spokeswoman Maria Zakharova said.
The news was harshly received in Turkey, a close ally of Azerbaijan.
Turkey’s ruling party spokesman Omer Celik tweeted: “We vehemently condemn Armenia’s attack on Azerbaijan. Armenia has once again committed a provocation, ignoring law.”
He promised that Turkey would stand by Azerbaijan and said “Armenia is playing with fire and endangering regional peace”.
Turkish presidential spokesman Ibrahim Kalin also took to Twitter to condemn Armenia, saying: “Armenia has violated the ceasefire by attacking civilian settlements … the international community must immediately say stop to this dangerous provocation”.
Nagorno-Karabakh is a mostly mountainous region of some 4,400 square kilometres (1,700 square miles) and lies 50 kilometres (30 miles) from the Armenian border.
Local soldiers backed by Armenia also occupy some Azerbaijani territory outside the region.
At the Vatican on Sunday, Pope Francis said that he was praying for peace between the two countries, urging them to “accomplish concrete deeds of goodwill and fraternity” to reach a peaceful solution through dialogue.