|Abdallah has been critical of the Syrian government on her English-language blog
Update: A US student based in Scotland has indentified himself as the author of the "Gay Girl in Damascus" blog, sparking an outcry from rights campaigners around the world.
Tom MacMaster, a 40-year-old Edinburgh University masters student, admitted on June 12 that he was "Amina Arraf", who had described "herself" as a Syrian political blogger.
The revelation comes after a number of questions had been raised about Arraf's identity. One of her alleged photos was actually a photo of a woman named Jelena Lecic, who lives in London and said she has never met anyone named Amina Arraf. And a 2007 post on Arraf's old blog suggested that at least some of her writings are fictional.
A female blogger has been abducted by armed men in the Syrian capital, Damascus, relatives and activists say.
Amina Abdallah Araf was seized on Monday evening, as she was walking in the area of the Abbasid bus station, according to her cousin, Rania O Ismail.
"Amina was seized by three men in their early 20's. According to the witness [a friend accompanying Abdallah], the men were armed", Ismail wrote on Abdallah's blog, A Gay Girl in Damascus.
"One of the men then put his hand over Amina's mouth and they hustled her into a red Dacia Logan with a window sticker of Basel Assad," she continued, referring to President Bashar al-Assad's brother who died in a car accident in 1994.
Abdallah, openly lesbian, holds dual Syrian and American citizenship.
Accused of 'Salafist plot'
Ismail wrote that her cousin's whereabouts were unknown, and that the family was trying to track her down.
"We do not know who took her, so we do not know who to ask to get her back. It is possible that they are forcibly deporting her," she wrote.
"From other family members who have been imprisoned there, we believe that she is likely to be released fairly soon. If they wanted to kill her, they would have done so. That is what we are all praying for."
Since mass protests erupted in Syria in March, Abdallah has been increasingly critical of the the government, writing on Sunday: "They must go, they must go soon. That is all there is to say."
On April 26, she wrote about how her father faced down two security agents who came to arrest her, threatening to rape her and accusing her of being a involved in a Salafist plot.
Mixing regime criticism with humour and poems, Abdallah has been outspoken about the situation for homosexuals and other subjects which are taboo in Arab culture.
Several Facebook pages calling for her release were set up on Monday and activists also launched a campaign on Twitter.
Syrian authorities had been cracking down on journalists and bloggers even before protests began.
A number of bloggers were arrested in February, and 20-year-old Tal al-Mallouhi, a 20-year-old girl, was jailed on charges on spying for a foreign country.