Relatives and families of imprisoned Syrians gathered in front of jails on Wednesday, waiting for the release of their loved ones after the Assad regime granted an extensive amnesty.

A crowd of hundreds waited in the center of the capital Damascus, with dozens camping out overnight holding a vigil that their missing family might be among those to be safely returned.

"I've been expecting my five children and my husband since 2014," Umm Maher said, waiting near the capital's Jisr al-Rais bridge, the main arrival point for buses entering the city.

"The oldest is 25 and the youngest 15. We have nothing to do with terrorism," she added, referring to what many say is a blanket charge often used to detain civilians.

Syrian regime leader Bashar Assad has issued several amnesty decrees during the country's devastating 11-year war, which broke out after the regime cracked down on mostly peaceful protesters.

But human rights activists said the recent release – following a decree issued on Saturday – is the most comprehensive in relation to terrorism charges.

The new decree calls for "granting a general amnesty for terrorist crimes committed by Syrians" before April 30, 2022, "except for those leading to the death of a person."

On Tuesday, the Justice Ministry said that "hundreds of prisoners have been released over the past two days in several regions."

The Britain-based Syrian Observatory for Human Rights says that more than 250 detainees have already been freed, with the Justice Ministry promising more will be released in the coming days.

Half a million people have been detained in regime prisons since the start of the war, with about 100,000 dying either under torture or due to poor detention conditions, according to the Observatory.

Activists also accuse the regime of torturing detainees to death, of rape, sexual assaults and extrajudicial executions.

Umm Abdo was waiting for her two sons, who disappeared in 2013.

"I hope they come back," she said. "I told my neighbor that she should hold me if I see them because I might faint. I don't even know if I will recognize them."

For the crowds waiting in Damascus, as of Wednesday, no prisoners had yet returned.