That’s all for us for tonight – but if you’re just checking in, here is a brief round-up of today’s developments:

• There are secret prisons around Syria yet to be discovered, according to a senior member of the White Helmets, who are investigating thousands of reports;
• The lightning rebel assault that stunned international observers over the past fortnight may have been boosted by a shipment of drones from Ukraine, according to a report in the US;
• In an interview with Sky News, a top commander in Syria warned a resurgent ISIS is starting to take advantage of the chaotic fall of Bashar al Assad;
• Part of the tomb of Mr Assad’s father was set on fire by Syrian troops;
• Our reporter on the ground got access to the deposed president’s abandoned home – giving a glimpse of his life of luxury;
• Among Mr Assad’s possessions was a signed picture of Queen Elizabeth II and Prince Philip, found in his packed “treasure room”;
• Syrian rebel leader Abu Mohammed al Jolani said people responsible for torturing and killing detainees under the Assad regime will not be pardoned by his government;
• The Israeli military said it has struck more than 350 military sites across Syria, destroying most of the country’s “strategic weapons stockpiles”.

Some of the details in this post may be distressing

As we’ve been reporting since the fall of the Assad regime, thousands have headed to Sednaya prison in the hope of finding loved ones who disappeared years ago.

Rights groups and activists have reported on the notorious facility – dubbed the “human slaughterhouse” by Amnesty International – for years.

But now the true scale of its horrors are beginning to come to light – and there may well be many other secret prisons around the country yet to be discovered.

According to Farouq Habib, deputy general manager of the Syrian Civil Defence Volunteer Organisation, the group has teams investigating “thousands of reports” about hidden facilities.

“As we speak now, our teams are still searching and looking for every location,” he said, speaking on The World with Yalda Hakim.

Underground search

Teams from the group, also known as the White Helmets, have been trying to access suspected hidden cells below Sednaya prison, but have only found one floor below the facility – not the three storeys some families have claimed there could be.

“There were allegations that there are three floors under the ground and people insisted,” he said.

“We believe there is nothing under that floor, but families were crying… they believed that they could be alive there because the number of the detainees, according to human rights organisations, is much higher than the number of people who were found there.”

He said they believe most of those people who are unaccounted for were executed and buried in mass graves.

“We had to respond to their cries, and we tried, but we couldn’t find,” he added.

‘All kinds of torture machines’

Our lead world presenter Yalda Hakim sent in this report from the halls of the prison itself.

Mr Habib said “there are all kinds of torturing machines”.

“We found there are people who are very traumatised because of the physical and mental status of the detainees who were released there,” he added.

“There were women and children who were born in that prison because the women were raped. They have had their babies there, and they were prisoners who lost their names.”

Other prisoners have “lost their minds”, he also said, and have forgotten where they came from.