US denounces 'detentions' of Assad opponents' relatives
The US has accused the Syrian government of undermining the Geneva II peace talks by detaining the relatives of opposition delegates.
Expressing Washington's "outrage", state department spokeswoman Jen Psaki called on Damascus to "unconditionally release all those unfairly arrested".
Among those held is Mahmoud Sabra, the brother of the National Coalition's legal adviser Mohammed Sabra.
The second round of the talks in Geneva broke down earlier this month.
UN mediator Lakhdar Brahimi said it was primarily because the Syrian government had refused to discuss the opposition's demands.
The National Coalition's delegates had wanted to focus on the implementation of the 2012 Geneva Communique, which calls for the creation of a transitional administration with full executive powers.
But the government wanted to address the elimination of "terrorism".'Assets seized'
Officials in Damascus routinely refer to all opponents of President Bashar al-Assad as "terrorists" and recently designated all National Coalition members as such, including civilians.
End Quote Jen Psaki US state department
The regime is not only defying the international community but also seeking to suppress the legitimate aspirations of the Syrian people”
Ms Psaki said the US government was outraged by reports that the Syrian authorities had "arrested family members of the Syrian opposition coalition delegation to the Geneva II talks, designated delegates as terrorists, and seized delegates' assets".
"We call on the regime to immediately and unconditionally release all those unfairly arrested, including Mahmoud Sabra, brother of Geneva delegation member Mohammed Sabra," a statement from her added.
"By targeting family members of opposition delegates participating in the Geneva talks, the regime is not only defying the international community but also seeking to suppress the legitimate aspirations of the Syrian people."
Opposition activists say tens of thousands of people have been detained in Syrian government detention centres since the start of the uprising almost three years ago. An estimated 50,000 people are unaccounted for, they estimate.
Last month, three former war crimes prosecutors said they had clear evidence of the "systematic killing" of about 11,000 detainees after examining 55,000 digital photographs smuggled out of Syria by a military police photographer who had defected.
They Syrian government said the report had no credibility as it was commissioned by Qatar, which funds opposition and rebel groups.
In a separate development on Thursday, 19 trucks carrying aid entered an eastern district of Damascus where rebels and government forces agreed a truce last month.
The convoy, which was organised by the International Committee of the Red Cross (ICRC) and the Syrian Arab Red Crescent, was the first to enter Barzeh since the truce.
Barzeh has experienced heavy fighting and bombardment in the past year, leaving much of the district in ruins.
The limited ceasefire was achieved by local residents mediating between rebel fighters and government forces.