Unbeknown to Hanna, her father had been dismissed as a minister, though he still went out early to get some exercise each day.
It was not until a few days after 9/11 – when the world was distracted by the al-Qaeda attacks on the US – that the country was to discover the full extent of Isaias’s displeasure in what became a watershed moment in Eritrea’s history.
In the early hours of 18 September, the security forces positioned themselves outside the homes of 11 senior government officials in the capital, Asmara, on the president’s orders.
Petros was picked up by security agents as he left in his tracksuit.
The family had no idea what had happened to him. Hanna and her three siblings went to stay with their paternal grandmother as their mother, Aster Yohannes, was away studying in the US.
It was only some days after Petros had disappeared that things became clearer, says Hanna about the painful memories.
“My classmates told me that my father sold out his country.
“That is when I understood how serious the situation was, and how people framed my dad and his colleagues who fought for the independence of their country. I was hurt.”
In the US, Aster was shell-shocked by what had happened – and was in a very bad way. She asked government officials if they could issue the children with passports – but they refused, telling her to come home.
After agonising about the situation for two years and reportedly receiving assurances from government officials, she packed her bags to return.
Hanna and her siblings desperately wanted her back – but they were also worried.
“I told her on the phone: ‘What if they arrest you?'” Hanna remembers.
“She insisted nothing would happen to her, saying: ‘I haven’t done anything wrong, and am only coming to raise my children.'”
Hanna says she learned later that President Isaias himself had promised Aster that she would be safe. But while the family waited at Asmara International Airport on 11 December 2003, she failed to emerge through arrivals with the other passengers.
Their hopes began to wilt along with the flowers they had brought: “It was a long, long wait. Eventually we gave up and went back home.
“First we called to the US, friends and relatives told us they saw her off at the airport.”
Then ominously an official called from the airport asking Aster to collect her luggage. That is when they realised she had arrived in the country but would not be coming home.
All pleas and requests for information fell on deaf ears in the months that followed. Instead Hanna’s grandmother was warned by authorities to stop inquiring.
The family later heard that Aster was being held in the infamous jail known as Karshelli in the heart of Asmara.
Hanna’s father is believed to be detained, with the others arrested on 18 and 19 September 2001, in the remote, hostile and highly secretive prison known as Ela-Ero, located in eastern lowlands north-east of Asmara. Accused of treason, none of them has ever been brought to trial or allowed to see their relatives.
At around the same time, the government also shut down all the fledgling independent newspapers and detained their editors and journalists – also believed to be imprisoned in Ela-Ero.
The Eritrean government – including its embassy in the UK – has not responded to the BBC’s request for comment regarding the whereabouts of the prisoners or whether or not they are alive.
Hanna, like many thousands of young Eritreans fleeing conscription and in search of better opportunities, left the country – travelling secretively over the border without a passport.
Now 35 years old, she is married and lives in the US, working as a trauma specialist – but still feels traumatised herself by how she lost her parents.
As she stares at old pictures of her parents, she worries her memories will fade of the happy times before their arrest – the laughter, the family gatherings, the birthday parties: “My dad always wanted to gather people in the house, they were good days.”
