By Tom Miles and Tom Perry
Syria's main opposition group has agreed to travel to Geneva, where the United Nations has opened peace talks to end the country's five-year-old war, but said it wanted to discuss humanitarian issues before engaging in political negotiations.
On the ground opponents of Syrian President Bashar al-Assad said they were facing a Russian-backed military onslaught, with hundreds of civilians reported to be fleeing as the Syrian army and allied militia tried to capture a suburb of Damascus and finish off rebels defending it.
UN envoy Staffan de Mistura invited the Syrian government and an opposition umbrella group to Geneva for "proximity talks", in which they would meet in separate rooms.
Until the last minute the opposition High Negotiations Committee (HNC) had refused to go, wanting an end to air strikes and sieges of towns and the release of detainees before talks could start.
Late on Friday (local time) the HNC said it was going to Geneva, having received guarantees that its demands would be met, but it made clear its engagement in the process would initially be limited.
"The HNC will go to Geneva to discuss these humanitarian issues which will pave the way into the political process of negotiations," spokesman Salim al-Muslat told the Arabic news channel al-Arabiya al-Hadath.
The HNC said it had drawn up a list of 3000 Syrian women and children in government prisons who should be released.
De Mistura opened the talks on Friday by meeting the Syrian government delegation. He said he expected to meet the HNC delegation on Sunday.
"They've raised an important point of their concern. They would like to see a gesture from the government authorities regarding some kind of improvement for the people of Syria during the talks, for instance release of prisoners, or some lifting of sieges," de Mistura said.
But he added that was a human rights point and "not even an issue to negotiate", and had strongly suggested the best way to get such measures implemented would be to start negotiating in Geneva, by proxy or directly.
Another major force, the Kurds who control much of northeast Syria and have proven one of the few groups capable of winning territory from Islamic State, were excluded from the talks after Turkey demanded they be kept away. The Kurds say their absence means the talks are doomed to fail.