A man standing on a wall outside Syria's notorious Saydnaya prison near Damascus is calling out names from a sheaf of papers in his hands.

Faces in the gathered crowds look up at him with a mixture of hope and fear. From the back of the crowd come outbursts of unsuppressed rage aimed at Bashar al-Assad.

Thousands of prisoners were freed from Assad's prisons after Syrian forces toppled his two-decade-long dictatorship on the weekend. Some of those who emerged were long feared dead. Days later, throngs of people are still making their way to Saydnaya hoping for news of loved ones who long ago disappeared into its bowels.

"I [had] four children in this prison," said Hosni Korno, clutching a record of their birth dates. "From 2012. Here in this prison." 

WATCH | CBC's Margaret Evans reports from outside Saydnaya prison:

Rescuers are searching to free detainees in Syrian prison

CBC’s Margaret Evans explains the search for survivors at the Sednaya prison near Damascus. Syria’s Civil Defence organization, known as the White Helmets, says it has searched the prison and found hidden prison cells. Many of the prisoners held there would have been political prisoners and dissidents.

A 2017 report by Amnesty International called Saydnaya a "slaughterhouse," documenting abuse on what it called an industrial scale including rape, torture and executions. People were often disappeared for being demonstrators, political dissidents, journalists, aid workers or students. The prison is suspected to have its own crematorium.

On Tuesday, the leader of the rebel group that put an end to Assad's regime promised to track down former government officials responsible for torture or other atrocities.

"We will not hesitate to hold accountable the criminals, murderers, security and army officers involved in torturing the Syrian people," said Abu Mohammed Al-Golani in a statement on Telegram. 

His forces broke open jails to free prisoners in cities from Aleppo to Homs to Damascus during their lightning offensive, which ended after Assad fled to Moscow; the Kremlin granted him asylum. 

Painfully thin inmates too weak to stand

There were horrifying scenes at Saydnaya when cell blocks were forced open to expose painfully thin inmates, some too weak to stand. The women's bloc included children born and held in captivity. 

One young rebel fighter outside the prison on Tuesday also carried a thick pile of papers with hand written names on them, this time a list of the people who worked there, including the guards.

"We want to give them to our leaders," said 25-year-old Abu Seif al-Dine, his face covered by a balaclava. 

"We prefer them to be taken for consideration at the international court. They did a lot of things." 

The London-based Syrian Observatory for Human Rights, a war monitor, estimates that some 30,000 people were killed at the prison between the start of the country's civil war in 2011 and 2020. 

Syria was already a police state with a vast network of prisons when Assad succeeded his father Hafez in 2000. 

But when widespread protests against his increasingly unpopular regime rose up as a part of the Arab Spring in 2011, Assad's prisons became one of his most brutal tools of repression, spreading fear each time anyone who spoke against him or asked for change disappeared into them.

Many of the prison locations in Syria were kept secret. Rights groups estimate that around 100,000 people went missing during the civil war, many of them behind those prisons' walls.

The lasting impact on countless families is evident as crowds flock to Saydnaya. Syrian rescue teams, including the White Helmets, have searched for hidden cells and say that everyone still alive has been released.

It's impossible to move through the crowds with a camera without being surrounded by people asking for a picture to be taken of a missing brother, or son, or friend.  

Ahmed al Ahmed says he applied for permission to visit two sons he believes were imprisoned at Saydnaya 16 times. Every request was followed by a rejection.

"We don't want peace with anyone until we get our families back," he said. 

"There are around 44 prisons in this area. Please deliver this message to the whole world."

Searching cells for loved ones

Some of those choosing to enter the prison to see the cramped and lightless conditions their loved ones endured often come out reeling; many women are overcome with emotion. 

Men clambering through basement rooms emerge carrying rope nooses they've found in rooms below.

At one point, rebels patrolling the grounds outside urge the crowd to quiet down. Sonar is being employed in the search for signs of secret underground chambers, even though the searchers have said there are none. 

But as long as hope is alive, so are their loved ones.