Four Syrian activists abducted in Damascus must be released immediately and unconditionally, influential regional and global human rights organisations say.
The abduction appears to be directly related to their human rights and humanitarian work.
Award-winning Syrian human rights defender and writer Razan Zaitouneh, her husband Wa'el Hamada, along with two colleagues, Nazem Hamadi and Samira Khalil, were seized on 9 December 2013 from an office of the Violations Documentation Center (VDC) and the Local Development and Small Projects Support (LDSPS) in Douma, part of Eastern Ghouta, in Damascus.
The area concerned is under the control of a range of armed opposition groups and is being besieged by Syrian government forces.
In a joint statement issued on 10 December 2013, the two organisations said that the abduction of Razan Zaitouneh was due to her activities as a founding member of these two NGOs.
Razan Zaitouneh recently won the 2013 International Women of Courage Award. She has also received the Anna Politkovskaya Prize and was awarded the European Parliament's Sakhorov Prize for Freedom of Thought in 2011.
"Civil society activists, writers, journalists and lawyers have borne a heavy price during the ongoing conflict in Syria, falling victim to unlawful killings, enforced disappearances, arbitrary detention and torture and other ill-treatment at the hands of government security forces … and armed opposition groups that disapprove of their activities," the representation says.
"All parties to the conflict should adhere to their obligations under international humanitarian law, which prohibits the abduction of civilians, hostage-taking and torture."
Co-signing organisations are the Alkarama Foundation, Amnesty International, the Cairo Institute for Human Rights Studies, the Euro-Mediterranean Human Rights Network, the Gulf Centre for Human Rights, the Humanist Institute for Cooperation with Developing Countries, the Institute for War and Peace Reporting, International Civil Society Action Network, the International Federation for Human Rights, International Media Support, Lawyers for Lawyers, PEN International, Reporters Without Borders, the SKeyes Center for Media and Cultural Freedom, the Syrian Centre for Media and Freedom of Expression, and the World Organisation Against Torture.