An advance team has arrived in Syria to prepare the way for Arab League monitors who will judge whether Damascus is honouring a plan it agreed last month to end violence that threatens to escalate into civil war.
The peace plan calls for a withdrawal of troops from the streets, release of prisoners and dialogue with the opposition. Thousands have died in a crackdown on protests against President Bashar al-Assad and, increasingly, in fighting between mutinous troops and security forces.
Arab League sources have said the advance team, led by top League official Samir Seif al-Yazal, comprises a dozen people, including financial, administrative and legal experts to ensure monitors have free access across Syria.
The main group of around 150 observers is to arrive by the end of December. Syria stalled for six weeks before signing a protocol on Monday to admit the monitors.
Syrian authorities said on Thursday 2,000 soldiers and security force members had been killed in nine months of unrest.
That was nearly double the previous figure given by Damascus and follows weeks of escalating attacks by army deserters and gunmen against forces loyal to President Bashar al-Assad.
United Nations human rights chief Navi Pillay has said some 5,000 people have been killed.
The British-based Avaaz rights group said on Thursday it had evidence of more than 6,237 deaths of civilians and security forces in the conflict, 617 of them under torture. At least 400 of the dead were children, it added.
The Syrian Observatory for Human Rights said Syrian forces surrounded and killed 111 people this week in the northern province of Idlib, in the deadliest assault since the uprising erupted in March.
The Observatory said another 21 people were killed on Thursday. Most were in the central city of Homs but some were in Idlib and the southern province of Deraa where the anti-Assad protests first broke out, inspired by the Arab Spring revolts which have overthrown rulers in Egypt, Tunisia and Libya.
The British-based Observatory's director Rami Abdulrahman said Assad's forces appeared to be trying to crush opposition in Idlib and Deraa before the arrival of the main monitoring team.
A politician in neighbouring Lebanon suggested Assad was trying to prevent any de facto "buffer zone" emerging in Idlib, near the Turkish border, once the monitors were in place.
France called Tuesday's killings in Idlib were an "unprecedented massacre". The United States said Syrian authorities had "flagrantly violated their commitment to end violence" while former ally Turkey condemned Syria's policy of "oppression which has turned the country into a bloodbath".
Idlib has been a hotbed of the protest movement. As in other centres of unrest, peaceful protests have increasingly given way to armed confrontations, often led by army deserters.
The main opposition Syrian National Council (SNC) said 250 people had been killed on Monday and Tuesday in "bloody massacres", including a local imam it said was beheaded. It urged the Arab League and United Nations to protect civilians.
The SNC demanded "an emergency U.N. Security Council session to discuss the (Assad) regime's massacres in Jabal al-Zawiyah, Idlib and Homs, in particular" and called for "safe zones" to be set up under international protection.
It also said those regions should be declared disaster areas and urged the International Red Crescent and other relief organisations to provide humanitarian aid.
Syrian officials say over 1,000 prisoners have been freed since the Arab League plan was agreed and the army has pulled out of cities. The government has promised a parliamentary election early next year as well as constitutional reform which might loosen the ruling Baath Party's grip on power.
Syrian pro-democracy activists are deeply sceptical about Assad's commitment to the plan. If implemented, it could embolden demonstrators demanding an end to his 11-year rule, which followed three decades of domination by his father.
Assad is from Syria's minority Alawite sect, an offshoot of Shi'ite Islam, and Alawites hold many senior posts in the army that he has deployed to crush the protests, mounted mainly by members of the country's Sunni Muslim majority.