"He was on his way back home from work, and he was abducted... from the streets," Mohammed Ghanem, senior political advisor for the Syrian American Council, told AFP.
Witnesses got a message back to his family and to his brother who now lives in Turkey, and it is feared that Mahmoud Sabra is incarcerated in the notorious Far Falastin, or Palestine Branch, jail near the Syrian capital.
"If you're held in this facility, one receives the worst kind of torture, things you can't even describe," said Ghanem.
The United States has already condemned Sabra's arrest and called for his unconditional release.
But Ghanem said it was part of a relentless campaign of intimidation by the regime of President Bashar al-Assad.
"There's been retaliation against literally everyone," he said.
"All of those who went to Geneva have been designated as terrorists, and all of their moveable and immovable assets have been seized. ... jewelry, furniture, cars stocks, money stashed in bank accounts," he said.
"This is their punishment for sitting across the table from regime delegates and trying to work out a plan for transition in Syria."
The second round of the UN-led talks in the Swiss city dubbed Geneva II, broke down in acrimony on February 15, only weeks after the warring parties sat down in January for the first time to seek a political settlement.
So far no date has been set for the talks to resume.
Ghanem said he believed UN-Arab League special envoy Lakhdar Brahimi would manage to get the talks going again, as the international community seeks an end to the brutal three-year war.
"But I think ultimately the talks will fail. No one believes that Assad will negotiate his own demise, his own departure," he said.
"He doesn't think he needs to negotiate because he thinks he has the upper hand on the ground.
"So unless conditions on the ground are created so they are conducive to talks, it will be one round after one round of talks, and time-buying just so Assad can continue his offensives."
The opposition has insisted the focus of the Geneva talks must be on creating a transitional government, without Assad.
The regime representatives meanwhile stubbornly insisted Assad's position was non-negotiable and refused to discuss anything beyond the "terrorism" it blames on its opponents and their foreign backers.
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Witnesses got a message back to his family and to his brother who now lives in Turkey, and it is feared that Mahmoud Sabra is incarcerated in the notorious Far Falastin, or Palestine Branch, jail near the Syrian capital.
"If you're held in this facility, one receives the worst kind of torture, things you can't even describe," said Ghanem.
The United States has already condemned Sabra's arrest and called for his unconditional release.
But Ghanem said it was part of a relentless campaign of intimidation by the regime of President Bashar al-Assad.
"There's been retaliation against literally everyone," he said.
"All of those who went to Geneva have been designated as terrorists, and all of their moveable and immovable assets have been seized. ... jewelry, furniture, cars stocks, money stashed in bank accounts," he said.
"This is their punishment for sitting across the table from regime delegates and trying to work out a plan for transition in Syria."
The second round of the UN-led talks in the Swiss city dubbed Geneva II, broke down in acrimony on February 15, only weeks after the warring parties sat down in January for the first time to seek a political settlement.
So far no date has been set for the talks to resume.
Ghanem said he believed UN-Arab League special envoy Lakhdar Brahimi would manage to get the talks going again, as the international community seeks an end to the brutal three-year war.
"But I think ultimately the talks will fail. No one believes that Assad will negotiate his own demise, his own departure," he said.
"He doesn't think he needs to negotiate because he thinks he has the upper hand on the ground.
"So unless conditions on the ground are created so they are conducive to talks, it will be one round after one round of talks, and time-buying just so Assad can continue his offensives."
The opposition has insisted the focus of the Geneva talks must be on creating a transitional government, without Assad.
The regime representatives meanwhile stubbornly insisted Assad's position was non-negotiable and refused to discuss anything beyond the "terrorism" it blames on its opponents and their foreign backers.
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