Syria is set to hand over a detailed plan for destroying its chemical arsenal Thursday, the international watchdog says, as a rebel attack near Damascus triggered power outages across the country.
But prospects for a peace conference, which the United Nations is trying to convene in parallel with the disarmament process, looked dim after key opposition leaders spurned efforts by Western and Arab powers to persuade them to attend.
On the ground violence raged unabated Wednesday, with rebels striking a gas pipeline that caused blackouts across Syria. An AFP correspondent in Damascus said he could see a huge fire blazing close to the airport, which is near the affected power station.
"A terrorist attack on a gas pipeline that feeds a power station in the south has led to a power outage in the provinces, and work to repair it is in progress," state news agency SANA quoted electricity minister Emad Khamis as saying.
The Syrian Observatory for Human Rights said besides the Damascus region power outages were reported in Aleppo in the north and Homs in the centre. "It is likely this was a large-scale operation planned well in advance," said Observatory director Rami Abdel Rahman.
In September, a similar outage was caused after a high voltage power line was sabotaged.
Also Wednesday a car bomb hit a checkpoint in a western suburb of Damascus, causing multiple casualties among the troops manning it, the Observatory said, and rebels shelled two of Damascus's main squares killing five people and wounding at least 22.
Meanwhile the Organisation for the Prohibition of Chemical Weapons said the Syrian government was expected to hand over its disarmament plan by Thursday.
The plan is the next step for Damascus under the terms of a US-Russian deal to head off military strikes on Syria which calls for all its chemical weapons and production facilities to be destroyed by mid-2014.
"We expect Syria's initial declaration of its chemical weapons programme within the next 24 hours," spokesman Michael Luhan told reporters Wednesday in The Hague, where the OPCW is based.
President Bashar al-Assad's regime has already handed over an inventory of its chemicals, weapons and facilities, and a joint UN-OPCW team has been in Syria since the start of the month inspecting and destroying them. The team has now checked 18 of 23 declared sites in Syria, destroying production equipment at almost all of them, Luhan said.
But parallel efforts by the United Nations to convene a peace conference in Geneva next month have run into resistance from the opposition, who are insisting on a raft of preconditions.
Leaders of the National Coalition -- the main opposition umbrella group -- insisted they will not attend unless regime change and Assad's departure are on the table.
A meeting in London Tuesday between opposition leaders and 11 governments from the Friends of Syria group produced little more than a joint statement that Assad should play no future role in government.
But behind the scenes Wednesday UN ambassador to Syria Robert Ford, who has built up a close relationship with the opposition leaders over the past years, huddled with key figures in Istanbul seeking to coax them to the negotiating table.
"Their participation is pivotal. We will continue encouraging them to attend, and that's why Ambassador Ford's on the ground talking to them right now in Istanbul," said deputy State Department spokeswoman Marie Harf.
The Assad regime retorted on Wednesday that no foreign party could be involved in deciding the country's leadership. "The Syrian people will not allow any foreign party to impose itself ... in choosing a government, or in determining its powers and tasks," the foreign ministry said.
It said the government was ready to attend the planned Geneva conference to "try its best to ensure its success without any preconditions or any foreign intervention".
The opposition is due to meet at the start of November to finalise its position on the Geneva talks.
But Coalition head Ahmad Jarba showed no signs of readiness to compromise. "The only thing we are willing to negotiate is a transfer of all power and then the departure of the mass killer (Assad)," he said.