Jihadists led by the radical Al-Nusra Front seized a strategic army base in the northern Syrian province of Aleppo on today, in a fresh setback for President Bashar al-Assad's regime, a watchdog said.
The Syrian Observatory for Human Rights also reported clashes in a northern Damascus district, the fiercest in the area since a revolt against Assad broke out in March 2001.
On the political front, the EU gave a vital boost to the newly-formed Syrian opposition coalition, describing it as the "legitimate representatives" of the Syrian people following talks in Brussels with its leader Ahmed Moaz al-Khatib.
Previously the EU recognised the opposition coalition as "legitimate representatives of the aspirations of the Syrian people," falling short of recognising it outright as a potential successor to Assad's regime.
EU foreign affairs chief Catherine Ashton said the statement - which comes ahead of a "Friends of Syria" meeting in Morocco this week - spoke for itself.
Foreign ministers found it "incredibly useful" to have met Khatib, she said.
And the European Union, winner of this year's Nobel Peace Prize, said at the award ceremony in Oslo that the 21-month conflict in Syria that has cost tens of thousands of lives was "a stain" on the world's conscience.
"Let me say it from here today," said European Commission president Jose Manuel Barroso. "The current situation in Syria is a stain on the world's conscience and the international community has a moral duty to address it."
Also on Monday the European Commission announced that it would provide another US$39 million in humanitarian aid to help people affected by the Syrian violence, bringing its total contribution to some 126 million euros.
The capture by Al-Nusra Front and allied jihadist groups of the base at Sheikh Suleiman dealt a blow to Assad's regime as it had been the last major military base west of Aleppo city still under army control.
But it also undercut the military influence of the mainstream rebel Free Syrian Army (FSA).
An AFP journalist who covered the clashes around Sheikh Suleiman said many fighters were from other Arab countries and Central Asia.
A rebel chief told AFP that no chemical weapons or surface-to-air missiles were found on the base.
"We control the whole base, all the zone is under our control. The whole region west of Aleppo up to the Turkish border has now been liberated. But no chemical weapons were found, or anti-aircraft missiles," said Abu Jalal.
The rebel chief headed the only unit of the mainstream rebel FSA which took part in the operation.
Also on Monday (local time) the army used warplanes and tanks to bombard rebel positions in Damascus province and violent clashes broke out in the north of the capital, the Observatory said.
Violence in Damascus has previously been focused on southern districts.
At least 64 people, among them 19 civilians, 26 soldiers and 19 rebels, were killed in violence across Syria on Monday, said the Observatory, which relies on activists and medics for its information.
The latest violence came two days ahead of a Friends of Syria nations meeting in Marrakesh, bringing together countries which support the anti-Assad revolt.
Arab and Western states will consider two key issues concerning the conflict - the political transition in the event of Assad's fall, and mobilising vital humanitarian aid as winter sets in.
Since the last meeting, in Paris in July, the number of people killed has risen from 16,000 to more than 42,000, according to the Observatory.
Meanwhile, a diplomatic source in Ankara said that US-made Patriot missiles will not be deployed right at Turkey's volatile border with Syria but rather a short distance away, in a bid to reassure Russia.
"We want to keep the missiles away from the border in order not to cause any misunderstanding with Russia and to make it clear that their deployment is purely to defend Turkish territory," the source said Monday.