Hungry and exhausted Armenian families jammed roads to flee homes in the defeated breakaway enclave of Nagorno-Karabakh. Some fled packed into the back of open-topped trucks, others on tractors. Grandmother of four Narine Shakaryan arrived in her son-in-law’s old car with 6 people packed inside.

Hungry and exhausted Armenian families jammed roads to flee homes in the defeated breakaway enclave of Nagorno-Karabakh, while the United States called on Azerbaijan to protect civilians and let in aid.

The Armenians of Karabakh - part of Azerbaijan beyond Baku's control since the dissolution of the Soviet Union - began fleeing this week after their forces were routed in a lightning military operation by Azerbaijan's military.

At least 13,550 of the 120,000 ethnic Armenians who call Nagorno-Karabakh home arrived in Armenia on the first day of the exodus, with hundreds of cars and buses crammed with belongings snaking down the mountain road out of Azerbaijan.

Some fled packed into the back of open-topped trucks, others on tractors. Grandmother of four Narine Shakaryan arrived in her son-in-law’s old car with 6 people packed inside. The 77km drive had taken 24 hours, she said. They had had no food.

"The whole way the children were crying, they were hungry,” Shakaryan told Reuters at the border, carrying her 3-year old granddaughter, who she said had become ill during the journey.

"We left so we would stay alive, not to live."

As Armenians rushed to leave the Karabakh capital, known as Stepanakert by Armenia and Khankendi by Azerbaijan, fuel stations were overwhelmed by panic buying. The authorities there said at least 20 people were killed and 290 injured in a massive blaze when a fuel storage facility blew up on Monday.

U.S. Agency for International Development (USAID) chief Samantha Power, in the Armenian capital Yerevan, called on Azerbaijan "to maintain the ceasefire and take concrete steps to protect the rights of civilians in Nagorno-Karabakh."