Thousands of Syrians marched Friday to test the regime's commitment to a UN-backed peace plan.
The hard-won truce to end a 13-month crackdown on dissent that has cost an estimated more than 10,000 lives appeared to be holding.
But French President Nicolas Sarkozy said he did not expect it to last, questioning President Bashar al-Assad's sincerity and appealed for observers to monitor his compliance.
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UN-Arab League peace envoy Kofi Annan, who brokered the ceasefire, urged Syria to let agencies deliver aid.
"Mr Annan is aware that we don't have a perfect situation in the country at the moment," his spokesman Ahmad Fawzi said. "There are detainees that need to be released," and "humanitarian access," is needed, he added.
Protesters rallied in the Qadam and Assali districts of Damascus, while other demonstrations took place in Irbin and Bibla outside the capital, according to videos posted on the Internet.
The Syrian Observatory for Human Rights said demonstrations were organised across the country, with tens of thousands taking to the street, mostly after Friday prayers.
"The numbers this time are higher than previous weeks," said Observatory head Rami Abdel Rahman.
Sporadic clashes broke out between troops and rebels at Khirbet al-Joz on the border with Turkey, the Observatory said.
Violence on Thursday killed at least 10 people, including seven civilians, and wounded dozens more.
Even so, the toll is markedly lower than in recent weeks, when there have often been scores of people killed on a daily basis.
But security forces killed six civilians in various cities around the country Friday, and two soldiers lost their lives.
After the ceasefire came into force at dawn on Thursday, Annan declared he was encouraged by reports that Syria was relatively calm and that the ceasefire appeared to be holding.
But as Assad's government and the rebels traded accusations of trying to wreck the ceasefire, Annan insisted that all parties implement the six-point peace plan.
The plan calls for the withdrawal of forces from urban areas, the release of arbitrarily detained people, freedom of movement for journalists and the right to demonstrate.
Despite the regime's commitment, the spokeswoman for the opposition Syrian National Council (SNC), Basma Qoudmani, said "we have concrete proof that heavy weapons are still in population centres."
The SNC, the most widely recognised opposition group in exile, and Internet-based activists called for peaceful demonstrations to test the government's readiness to accept public shows of dissent.
"We call on the people to demonstrate and express themselves... The right to demonstrate is a principal point of the plan," SNC head Burhan Ghalioun told AFP.
Qoudmani added: "The real test (of the ceasefire) will be if there is shooting or not when people demonstrate."
The Syrian Revolution 2011 activist group called on Facebook for protests on Friday -- the Muslim day of rest when the demonstrations have been the largest after noon prayers -- under the rallying cry: "A revolution for all Syrians."
But the interior ministry insisted people wanting to demonstrate had to have permits.
At the United Nations Security Council in New York, Russia on the one side and the United States and its allies on the other submitted rival draft resolutions for a vote by the 15-nation body.
The two sides argued over whether Syria should give immediate guarantees of freedom of access to the mission and whether the council should warn President Assad of further measures if he does not keep commitments.
On Thursday, special envoy Annan asked for a quick resolution approving observer mission so that the advance party can leave early next week.
But the vote is now not expected until Saturday.
The rival resolutions, both obtained by AFP, authorize the deployment of up to 30 unarmed military observers. The UN eventually wants at least 200 monitors there.
The United States, Britain, France, Germany, Morocco and Colombia registered one text for a vote demanding "full, unimpeded, and immediate freedom of movement" for the mission.
It said Assad must "implement visibly" commitments he made to Annan and would force the council to "consider further measures" if Syria does not carry out the promised actions.
Russia submitted a shorter version of the same text taking out the demand for "unimpeded" access by the observers and the warning of new measures. It also takes out a condemnation of human rights abuses in Syria.
Meanwhile in Turkey, which is hosting around 25,000 Syrian refugees, Foreign Minister Ahmet Davutoglu said international aid had started to arrive.

