But Armenian officials were quick to deny the claim that Shusha had been seized.
Azeri President Ilham Aliyev said on Sunday his country’s forces had taken Shusha, the second-largest city in the Nagorno-Karabakh enclave.
Armenian officials immediately denied the claim.
If accurate, this would be a major strategic victory over the region’s ethnic-Armenian separatists.
“With great pride and joy, I inform you that the town of Shusha has been liberated,” Aliyev said in a televised address to the nation, as Armenian officials reported that “heavy fighting” for the city continues.
Aliyev said November 8 would “go down in the history of the Azerbaijani people” as the day “we returned to Shusha”.
The town and surrounding areas have seen fierce fighting in recent days, as Azerbaijani forces seek to make further gains six weeks after new clashes broke out over Nagorno-Karabakh.
The city, called Shushi by Armenians, is of cultural and strategic importance to both sides and is located 15km (9 miles) south of the enclave’s largest city, Stepanakert.
At least 1,000 people have died in nearly six weeks of fighting in and around Nagorno-Karabakh, a mountainous enclave internationally recognised as part of Azerbaijan but populated and controlled by ethnic Armenians.
Shortly before Aliyev’s announcement, the Armenian government said on Twitter that “heavy and decisive fighting continues for Shushi” and called the taking of the town “an unattainable pipe dream for Azerbaijan”.
“Over the night, the most ferocious combat has unfolded in the vicinity of Shushi,” Armenian defence ministry spokeswoman Shushan Stepanyan said. “Despite heavy destruction, the fortress city withstands the blows of the adversary.”
Nagorno-Karabakh is within Azerbaijan but has been under the control of local ethnic Armenian forces backed by Armenia since 1994. The latest outbreak of fighting started on September 27 and has left hundreds – if not thousands – dead.
Aliyev vowed to continue the fighting until Armenia withdraws from the territory.