So far more than 28,000 of the 120,000 Armenians of Karabakh, a region internationally recognised as part of Azerbaijan, have crossed in the border into Armenia, a country of about 2.8 million.

A military victory by Azerbaijan over the enclave, which was previously beyond Baku's control, a week ago has triggered one of the biggest movements of people in the South Caucasus since the fall of the Soviet Union.

The hairpin mountain road snaking out of Karabakh towards Armenia was choked with people. Many slept in cars or searched for firewood to warm themselves by the side of the road.

"I left everything behind. I don't know what is in store for me. I have nothing. I don't want anything," Vera Petrosyan, a 70-year-old retired teacher, told Reuters on Tuesday at the large Soviet-era hotel on the Armenian side of the border with Azerbaijan that is now her home.

"I would not want anybody to see what I have seen," she added, reflecting on the shootings, the hunger, turmoil and suffering she witnessed before escaping to Armenia.

Azerbaijan's 24-hour offensive in Karabakh came amid a blockade imposed on the enclave last December. It is not clear exactly what happened before the Karabakh leadership agreed to a ceasefire. Azerbaijan says civilians were not harmed.

Armenia and Azerbaijan have fought two wars over the enclave in 30 years -- with Azerbaijan gaining back swathes of territory in and around Nagorno-Karabakh in a six-week conflict in 2020.

Azerbaijan President Ilham Aliyev said that the rights of Armenians will be respected but said his "iron fist" had consigned the idea of an independent ethnic Armenian Karabakh to history and that the region would be turned into a "paradise."

The Armenians of Karabakh told Reuters they did not want to live as part of Azerbaijan and feared ethnic cleansing at the hands of Azerbaijan, which has repeatedly dismissed such claims as nonsense.

Some took down statues to their heroes

FIRE AND DIPLOMACY

As thousands rushed to leave, there was a major explosion at a fuel depot in the Askeran district of Nagorno-Karabakh on Monday, according to the local authorities. It was unclear what caused it.

There were conflicting details about the toll of the blast but the ethnic Armenian authorities said at least 68 had been killed, 105 were missing and nearly 300 were injured.

The badly injured were evacuated by helicopter to Armenia as the roads out were so jammed with traffic that a journey of just 77 km (48 miles) to the border was taking at least 30 hours.

The Karabakh crisis has shifted alliances in the South Caucasus region, a patchwork of ethnicities wedged between the Caspian and the Black seas where Russia, the United States, Turkey and Iran vie for influence.

Armenia, which was aligned with Russia, has rowed in public with Moscow which in turn has warned Armenian Prime Minister Nikol Pashinyan, who is facing calls to resign, to stop flirting with the West.

The United States, home to the second largest Armenian diaspora in the world after Russia, sent senior officials to Armenia to show their support.

U.S. Secretary of State Antony Blinken asked Azerbaijan's Aliyev on Tuesday "to emphasize the need for Azerbaijan to refrain from further hostilities in Nagorno-Karabakh and provide unhindered humanitarian access," State Spokesperson Matthew Miller said.

"The Secretary urged President Aliyev to commit to broad amnesty and allow an international observer mission into Nagorno-Karabakh," Miller said.

Aliyev told Blinken "that military facilities only had been targeted during the anti-terror measures, which lasted less than 24 hours, and civilians had not been harmed," according to statement by Azerbaijan's presidential office.

"President Ilham Aliyev underlined that respective activities are underway to ensure the rights of Armenian residents living in the Karabakh region," it said.

(This story has been refiled to fix a typo in the word 'lightning' in paragraph 1)