The family of a Syrian dentist who was arrested along with her six children has told the BBC they are still hoping to find them.
Meanwhile, the daughter of a US-based psychotherapist who was snatched in 2017 and is thought to be dead says she has been buoyed by videos of people who were declared dead being found alive.
As rebel forces swept across the country in recent weeks, they freed thousands of political prisoners held in government jails - including the notorious Saydnaya prison near the capital, Damascus.
But with torture and executions commonplace in these places under Bashar al-Assad's government, many are still waiting to see if their relatives are among those freed
Rania Al-Abassi was arrested from her home in Damascus in March 2013 by Syrian military intelligence officers. Her children, aged between two and 14 years old, were taken to prison with her.Her husband, Abdul Rahman Yasin, was arrested the day before.
Rania's sister, Naila Al-Abassi, a doctor living in Saudi Arabia, told the BBC "we cannot accept that Rania was killed".
"Since the fall of the regime, we really hope we can see Rania and her kids again. Especially, we want to see her six children."
Naila Al-Abassi says her family are actively searching for Rania and her children
At the time of their arrest, Abassi's children - Dima, Entisar, Najah, Alaa, Ahmed and Layan - were 14, 13, 11, eight, six and two respectively.
"They took Rania with her kids and since that day we don't know anything about them," Naila said.
A female inmate who was released told the family in 2013 that she heard the voices of children in the prison, two weeks after the arrest.
Now that prisoners have been released, family members on the ground have visited the prisons to try to find them.
"We are watching the news and seeing people released from the prisons and looking at the videos to see if we can see them," Naila said.
"But the prisons have been opened and we haven't seen Rania yet. It is unbearable."
"We were waiting for this day for 13 years," she added. "But our wounds are still fresh now as if it happened yesterday."
Naila Al-Abassi Rania Al-Abassi with her husband and childrenNaila Al-Abassi
The Abassi family before they were arrested
'The FBI told us he was dead but they did not have a body'
Majd Kamalmaz, a psychotherapist from Texas, disappeared in Syria in 2017. His daughter, Maryam, told the BBC she is still trying to find out what happened to him.
Kamalmaz had travelled to Damascus to visit an elderly family member.
On the second day of his trip, Mr Kamalmaz - who was born in Syria but grew up and lived in the US - was stopped at a Syrian government checkpoint in Damascus, and has not been seen or heard from since that day.
Earlier this year, US intelligence officials told his family they had credible, classified information that he died in prison.
Maryam Kamalmaz Maryam Kamalmaz with a photo of her father Maryam Kamalmaz
Maryam Kamalmaz has renewed hope after seeing reports that people declared dead were still alive
But Maryam Kamalmaz refuses to give up on the idea that her father may still be alive.
"The FBI told us he was dead - but they did not have a body or any concrete information," she said.
"We are seeing stories of people [who] were declared dead and given death certificates and then they actually turned out to be alive.
"It renews our hope to find him alive. But if we don't, then at least we want to find his remains and have some sort of closure."
Maryam added: "We have people inside Syria going to the hospitals with high hopes, as well as to Saydnaya prison.
"I keep looking at the pictures and videos of people coming out of the Saydnaya prison, and thinking maybe I will see him there."
Maryam said she does not know why her father was kidnapped. Her family believe he may have been being held as leverage by the Assad family because he was American.
In the hours after the collapse of Bashar al-Assad's regime in Syria, hundreds have descended on the site which for many most encapsulated his oppressive rule: the Saydnaya prison.
The notorious military complex has been used to detain tens of thousands of people who fell foul of the Syrian government over the decades.
Among those searching for people who have vanished inside its walls was Jwan Omar, a Syrian living in Turkey.
He travelled to Saydnaya prison on Sunday to search for his father-in-law who disappeared in 2013, after being arrested by the regime who accused him of helping the opposition.
"I went to the prison and showed photos of my father-in-law but nobody recognised him," Omar told the BBC.
"My wife dreamed for 11 years of finding her father. Our hopes were raised when we heard the prisoners were released, but my wife has been crying since yesterday."
He was disappointed to be told that many prisoners had been moved to another location.
Sharvan Ibesh Dr Sharvan Ibesh witnesed chaotic scenes outside Saydnaya prison as hundreds searched for family membersSharvan Ibesh
Dr Sharvan Ibesh witnesed chaotic scenes outside Saydnaya prison on Sunday night
Omar travelled to the prison with his friend Dr Sharvan Ibesh, chief executive of the Syrian aid group Bahar, who has been helping with the search.
Dr Ibesh described scenes of "chaos" at the prison, with hundreds of people trying to find their loves ones.
Dr Ibesh continued: "Hundreds of people were coming out of the prison and we were told we could not come in because so many people were getting in the way of the rescuers."
Syrian civil defence group, the White Helmets, has been searching for inmates at Saydnaya following accounts from prisoners of secret entrances to underground cells, though none have been found.
Fayzah Nadaf Mustafa was a baby when his father was arrested and taken to Saydnaya prison
Fayzah Nadaf
Mustafa was a baby when his father was arrested and taken to Saydnaya prison. "I hope he comes back. I have never heard his voice," he said.
Since the fall of Assad, many families have had renewed hope that they might find loved ones missing in prisons.
One such family is the Nadaf family from Idlib, who are currently searching for Thaer Nadaf who was arrested and sent to Saydnaya in 2011.
Thaer had two children - a baby and a two-year-old - at the time he was arrested.
His son Mustafa, who is now 12, told the BBC: "I hope he comes back. I swear I miss him, I have never heard his voice."
Thaer's mother Fayzah Nadaf said "nobody knows the reason why he was arrested".
She has sent her other son - Mohammad - to the prison in Damascus to find him.
A doctor who left the prison two months ago informed them that he was still alive. They believe he is being held in the underground section of the Saydnaya complex.
"I am looking forward to seeing my son again," Fayzah said. He has been missing for 12 years, and all the time I prayed that he could see his children again."
Sharvan Ibesh Al-Salam mosque in Damascus is a hub where prisoners are taken to try to find their familiesSharvan Ibesh
Al-Salam mosque in Damascus is a hub where prisoners are taken to try to find their families
A mosque 20km away is being used as a meeting place for released prisoners and their families.
When Ibesh visited there on Sunday, he saw several newly freed people clearly in a traumatised state, he told the BBC.
A group of people surrounded two men who had just been released, trying to help them.
"[They] had been held in the prison for several years and they were disorientated," Ibesh said. "They didn't even know the time zone."
"People around them were asking 'what's your name' and 'how old are you?', but they could not even answer those questions."
It was hard to tell how old they were from looking at them, Ibesh said, adding: "The men were totally lost, they were just staring ahead."
While there have been many family reunions since the prisoners were released, the search continues for many others.
The Assad regime imprisoned hundreds of thousands of political prisoners. The Turkey-based Association of Detainees and The Missing in Saydnaya Prison (ADMSP) group described Saydnaya as a "death camp".
Throughout the civil war, which began in 2011, government forces held hundreds of thousands of people in detention camps, where human rights groups say torture was common.
