The Assad regime detained these 6 Syrian kids with their parents in 2013. Where are they now?

Children's school uniforms hung on the door. Their academic workbooks lay on their desks. Toys covered in dust were still sitting on the floor.

That's how Naila Al-Abbasi found her sister Rania's apartment in Syria, nearly 12 years after she was detained alongside her six children and thrust into the former regime's secret network of prisons and detention facilities.

Al-Abbasi had travelled from Saudi Arabia to visit the home in Dummar Project, an affluent neighbourhood northwest of the Syrian capital, Damascus, on Feb. 25.

"The smell of murder fills the house. The walls and curtains sad as if they were mourning their separation," Al-Abbasi posted on Instagram.

She found every corner covered with dirt. The carcasses of birds who flew into the home were scattered on the floor. 

It was once a bright and busy home to six children: Dima, 13; Entisar, 12; Najah, 11; Alaa, 8; Ahmed, 6; and Layan, 1.

For years, Hassan Al-Abbasi, Rania's brother, has been demanding information on their whereabouts.

He has actively searched for the children following the ouster of Bashar al-Assad's government last December. But his calls have gone unanswered, with no word on the family's fate since March 2013.

"The situation is very difficult, because none of the children have turned up and it was the first time our family has entered the home in 12 years," Hassan told CBC News from Ottawa, where he lives with his wife and children.

"It was very painful."

On March 9, 2013, members of Assad's military intelligence arrested Rania Al-Abbasi's husband, Abdul Rahman Yasin, in their home, before returning to loot all the gold and money, seize three cars, computers and mobile phones, along with passports and ownership documents of their properties and Al-Abbasi's dental clinic.

Two days later, intelligence members returned to arrest Al-Abbasi, along with her six children and secretary Majdoline Al-Qady, who happened to be with them at the time. 

The parents were accused of providing humanitarian assistance to those in need during the Syrian revolution, which erupted in March 2011.

Al-Abbasi's case quickly became one of the most prominent in Syria, highlighting the issue of disappeared detainees — both parents and children.