Syria's opposition leader, Sheikh Moaz al-Khatib , has threatened to call off his offer of negotiations unless President Assad agrees to release all female political prisoners, AP reported on Thursday.
Speaking to the BBC's Arabic service, al-Khatib said the women must be released by Sunday in order for the talks to begin. The rebel leader had previously urged Assad to send his deputy to negotiate on an exit strategy  with the opposition.
According to international NGO, Human Rights Watch, the Syrian regime has 27 'detention centers' , holding political prisoners where inmates are often subjected to torture.
There were 4,000 political prisoners in Syrian in 2006, according to the Syrian Human Rights Committee  but since the beginning of the 2009 uprising, many more have been detained.
Al-Khatib said on Wednesday that the Syrian government is holding 160,000 people over the uprising although he did not state how many of these were women.