Among the thousands of people fleeing the five-week-old conflict in Ethiopia's Tigray region are a few dozen men, women and children from Eritrea, one of the world's most authoritarian states.

They were already living as refugees in Tigray, which had long been a safe haven for them during years of conflict and repression in Eritrea.

But when Ethiopian Prime Minister Abiy Ahmed's government launched a military operation against Tigray's ruling party, the Eritrean refugees' illusion of safety was shattered as violence escalated around their camps.

"Suddenly soldiers came to our camp and they started shooting," Kheder Adam told AFP in a Sudanese refugee camp. "The situation was very serious. There was a lot gunfire."

Kheder and his family had originally settled in one of the refugee camps in the Sheraro area of Tigray near the Eritrean border around two years ago, he said.

For years, Ethiopia and Eritrea had been officially in a state of war.

In 2018, Abiy took power, ending years of political dominance by the Tigray People's Liberation Front -- sworn enemies of Eritrean President Isaias Afwerki.

Abiy and Afwerki signed a historic peace agreement that same year, winning the Ethiopian leader the Nobel Peace Prize.

After the dramatic shift in alliances, Abiy's forces launched their operation in Tigray on November 4, Eritreans who had long benefitted from protection in Ethiopia appear to have become a target.

Since then, a few Eritrean refugees have managed to escape to Sudan.

The UN, meanwhile, has expressed fears for the safety for those still in Tigray, home to some 96,000 Eritrean refugees living in four refugee camps.

- 'Refugee again' -

Kheder, 30, who was separated by the recent violence from his wife and two children, aged three and one, was among several Eritrean refugees interviewed by AFP at a reception centre for new arrivals from Ethiopia in Hamdayit on the eastern Sudanese border.

"Some of the soldiers were Eritreans, some of them were (Ethiopian) federal soldiers," said Kheder, of the attack on the camp in Tigray.

"They were shooting at all people. All -- women, men, children," he said.

His comments were echoed Friday by a US State Department spokesperson -- though the Ethiopian government, a US ally, has denied the claim.

"I feel worried and sad to be a refugee again. There I was a refugee, and here I am also a refugee. It's really difficult," said Kheder.

He cited Eritrea's notorious policy of universal, indefinite conscription as one reason why he fled his home country in the first place.

"They forced us" to undergo a mandatory national service in Eritrea, he said. "That's why we decided to go to Ethiopia."

The Eritrean regime once used its war against Ethiopia to justify its system of universal conscription.

But the system remains in place despite the fact that the war ended in the year 2000, followed by the peace agreement in 2018.

Rights groups say Eritrea's national service often extends for years and any act of desertion or perceived disobedience leads to