By Khaled Yacoub Oweis and Stephanie Nebehay
GENEVA, Jan 30 (Reuters) - Opposing sides in Syria's civil war stood together to observe a minute of silence on Thursday in honour of the tens of thousands killed in the three-year conflict, a rare symbol of harmony a week into peace talks that have so fare yielded no compromise.
The first talks between President Bashar al-Assad's government and his foes have been mired in rhetoric since they began last Friday. The two sides took a first tentative step forward on Wednesday by agreeing to use the same 2012 roadmap as the basis of discussions to end the civil war, although they disagreed about how talks should proceed.
U.N. mediator Lakhdar Brahimi said on Wednesday he does not expect to achieve anything substantive in the first round which ends on Friday, but hopes for more progress in a second round starting about a week later.
Opposition delegate Ahmad Jakal said his delegation's head, Hadi al-Bahra, proposed the minute of silence and all sides stood up, including Assad's delegation and Brahimi's team.
"All stood up for the souls of the martyrs. Symbolically it was good," Jakal told Reuters.
Diplomats said there had been no progress on humanitarian issues and that a U.N. aid convoy has been waiting fruitlessly to enter the rebel-held Old City of Homs, where the United States says civilians are starving.
If there is no breakthrough on Homs this week, it would give the opposition delegation, mostly comprised of exiles, little to show for their decision to participate. Other factions with more power on the ground in Syria are opposed to the talks.
The 2012 plan sets out stages to end the conflict, including a halt to fighting, delivery of aid and agreement on setting up a transitional government body by mutual consent.
U.S. and Russian officials, co-sponsors of the conference, are in Geneva advising the opposition and Syrian government delegations, their respective allies.
Syrian deputy foreign minister Faisal Mekdad, one of the most influential players, was meeting with Russian officials later in the day in Geneva, diplomatic sources said.
While the opposition wants to start by addressing the question of the transitional governing body, the government says the first step is to discuss terrorism.
Damscus uses the word "terrorist" to describe all rebel fighters; Western countries have declared some Islamist groups among the rebels to be terrorists but they provide support for others they consider to be legitimate fighters in the civil war.
There was still no sign of a breakthrough in attempts to relieve the suffering of thousands of besieged residents of the rebel-held Old City of Homs, an issue that had been put forward to break the ice and build confidence at the start.
"The U.N. convoys are ready, we are waiting for clearances so we can provide this aid in a secure manner," Jens Laerke, spokesman of the U.N. Office for the Coordination of Humanitarian Affairs (OCHA), told Reuters on Thursday.
U.N. trucks must be able to enter besieged areas with security guarantees and the distribution of goods must be carried out in a safe way for the beneficiaries, he said.
Syria's biggest city Aleppo took some of the heaviest aerial bombardment of the conflict in the past week, including the dropping of indiscriminate "barrel bombs" - crude drums of high explosives tossed from helicopters - that killed and wounded dozens, opposition delegate Ahmed Ramadan told Reuters.
New York based watchdog Human Rights Watch said on Thursday that the Syrian authorities had flattened seven residential districts for no apparent military objective other than to punish civilians living among rebels who had already fled.