Syrian authorities have freed dozens of women prisoners and cleared a prominent young blogger for release in one of the final stages of a three-way hostage deal, a monitoring group said on Thursday.

President Bashar al-Assad's government has released 61 women over the past two days as part of the Qatari- and Turkish-brokered deal, the British-based Syrian Observatory for Human Rights said.

A Syrian court also granted amnesty to Tal al-Mallohi, a blogger arrested while in her late teens more than a year before the revolt in Syria began in March 2011, the Observatory said.

Mallohi, the grand-daughter of a former minister, was detained for political writing in 2009. The pro-opposition Observatory said her release was imminent.

The release of around 200 detained Syrian women was the main demand of kidnappers in northern Syria who had held nine Lebanese men hostage for 17 months. Those hostages and two Turkish pilots abducted in August by Lebanese gunmen in retaliation were freed last week.

The kidnappings highlight how complex and regionalised Syria's 2-1/2-year-old conflict has become. The civil war, which emerged after a violent response to peaceful protests against four decades of Assad family rule, has acquired sectarian dimensions that have pulled in neighbouring countries.