An opposition leader, rights activist and long-time dissident in Syria's rebel-held city of Raqa has been abducted, a watchdog said on Monday, Alarabiya reported.
"The Syrian Observatory for Human Rights has learnt of the abduction by an armed group of lawyer, human rights activist and head of Raqa city's (opposition) local council Abdullah al-Khalil," the Britain-based group said.
It condemned the kidnapping and demanded "his immediate release".
Khalil was abducted as he left the local council's headquarters in Raqa on Sunday morning, added the watchdog, which relies on a broad network of activists, doctors and lawyers for its reports.
Syrian regime troops have not been inside the city since March this year, when Raqa became the first and only provincial capital to fall to rebels since the uprising against President Bashar al-Assad broke out more than two years ago.
The local council led by Khalil has worked with rebel groups and campaigned for the return of civilian life, despite frequent aerial bombing by Assad loyalists.
Khalil has been abducted before, telling Human Rights Watch researchers last month that he was held by security forces less than two months into the anti-Assad uprising.
He was transferred to 17 different security branches while in detention, HRW said.
Rights groups say tens of thousands of people are missing or in detention in Syria.
An activist in Raqa blamed radical Islamists who refused to withdraw from the city's residential areas for Khalil's kidnapping.
Khalil, also known as Abu Sara, "has been kidnapped just days before new local council elections. I think the only way he will get released is if some kind of deal is struck", said the activist who spoke to AFP on condition of anonymity.
"People used to like Ahrar al-Sham and Al-Nusra Front (powerful rebel groups). Now they're just stealing the country from us," said the activist, adding that several other local personalities and non-jihadist rebel leaders had been kidnapped or killed in the area in recent weeks.
The activist said that in Raqa, even within jihadists' ranks there is division.
"The Islamic State of Iraq and Greater Syria is becoming more powerful than al-Nusra Front in some areas," he said.
He said the Islamic State of Iraq and Greater Syria had tried to bring the jihadist al-Nusra Front under its full control, but could not.
"Now they are two groups, competing against each other for influence," said the activist, who is well-informed on political developments in rebel-held areas.