with Azerbaijan and Armenia accusing each other of serious violations and crimes against civilians.

The ceasefire, clinched after marathon talks in Moscow advocated by President Vladimir Putin, was meant to halt fighting to allow ethnic Armenian forces in Nagorno-Karabakh and Azeri forces to swap prisoners and war dead.

The Moscow talks were the first diplomatic contact between the two since fighting over the mountainous enclave erupted on Sept 27, killing hundreds of people. The enclave is internationally recognised as part of Azerbaijan, but is populated and governed by ethnic Armenians.

Both sides accused one another of breaking the ceasefire almost immediately on Saturday, and Azerbaijan gave the impression in public comments from top officials that it saw it as only a brief and temporary breathing space anyway.

On Sunday, Azerbaijan accused Armenia of heavily shelling a residential area in Ganja, its second largest city, in the early hours of the morning, and of hitting an apartment building.

The Azeri Prosecutor General’s Office said five people had been killed and 28 wounded in the attack, which it said violated the norms of the Geneva Convention on the protection of civilians.

The Armenian defence ministry called the Azeri allegations “an absolute lie” and accused Azerbaijan of continuing to shell populated areas inside Karabakh, including Stepanakert, the region’s biggest city.

A Reuters photographer in Ganja saw rescue workers carrying one dead person from the ruins of a large apartment building on Sunday morning. The structure had been almost levelled. An excavator was clearing the debris.

Buildings and cars in the immediate vicinity had also been severely damaged.Reuters could not independently verify Azeri assertions about the number of fatalities.

Azerbaijan accused Armenia of also launching an unsuccessful rocket attack on an Azeri hydro-electric power station in Mingachevir. Ethnic Armenian forces in Karabakh denied the assertion.

Arayik Haratyunyan, the leader of ethnic Armenian forces in Nagorno-Karabakh, described the situation as relatively calm on Sunday morning, but said he did not know how long it would last and that the frontline remained tense.

He accused Azeri forces of trying to unsuccessfully take control of the town of Hadrut, and said the process of the two sides exchanging prisoners should have started on Sunday, but that it was unclear if and when that would happen.

Renewed fighting in the decades-old conflict has raised fears of a wider war drawing in Turkey, a close ally of Azerbaijan, and Russia, which has a defence pact with Armenia.

The clashes have also increased concern about the security of pipelines that carry Azeri oil and gas to Europe.

The fighting is the worst since a 1991-94 war that killed about 30,000 people and ended with a ceasefire that has been violated repeatedly.