Syria ceasefire appears to be holding

China welcomed Syria\'s decision to uphold a "comprehensive ceasefire" describing it as a step towards a political solution, as Russia called for more time for the peace plan to work.

And the opposition urged people to take advantage of the ceasefire and stage demonstrations against the regime of President Bashar al-Assad.

After breaking a commitment to pull back forces from population centres by Tuesday under the agreement brokered by former UN chief Kofi Annan, there were still no signs of a withdrawal, monitors said.

"The situation is calm in all regions," said Rami Abdel Rahman of the Britain-based Syrian Observatory for Human Rights.

A "few explosions" were heard in the town of Zabadani, just outside the capital, shortly after the ceasefire came into effect, Abdel Rahman told AFP in Beirut.

"There has not been any movement indicating a withdrawal of tanks," he added.

Activists in Damascus, Hama, and Daraa reported that calm has prevailed since the ceasefire deadline.

The reports could not be verified due to the Damascus government\'s curbs on media.

"The test will be tomorrow, when demonstrators take to the streets" after the Muslim Friday prayers, a traditional high point for protests, said activist Muaz from Damascus.

Just hours before the deadline expired at 6:00 am (0300 GMT), the military unleashed a lethal offensive against protest centres, killing 25 civilians on Wednesday, including 10 in the rebel stronghold of Rastan, said the Observatory.

That was the same day that Annan, serving as a peace envoy for the UN and the Arab League, said he received a letter from Syria promising to "cease all military fighting throughout Syrian territory as of 6:00 am."

But the letter reserved the right "to respond proportionately to any attacks carried out by armed terrorist groups," a phrase Assad\'s government uses to describe opposition forces.

US President Barack Obama and German Chancellor Angela Merkel agreed in a telephone call that the UN Security Council, which gave its blessing to Annan\'s plan, needed to "take more resolute action" on Syria.

The United Nations estimates more than 9,000 people have been killed since March 2011 as Assad\'s forces crush the latest in a series of uprisings against authoritarian leaders in the Arab world.

Susan Rice, the US envoy to the United Nations, said Assad\'s regime has in fact intensified violence since it first committed to Annan\'s six-point plan on April 1.

"Its commitments therefore have little, if any, credibility ... given that track record," Rice said.

Annan\'s plan calls for the withdrawal of forces from urban areas, a halt to fighting, a daily two-hour humanitarian truce, the release of arbitrarily detained people, freedom of movement for journalists and the right to demonstrate.

The opposition Syrian National Council said both it and the rebel Free Syrian Army, a ragtag force of mainly army defectors, were committed to the truce but also voiced doubts about the regime\'s commitment.

SNC chief Burhan Ghalioun called on people to demonstrate "because the right to demonstrate is a principle point of the plan of Annan," he said.

Ahead of the ceasefire, foreign ministers of the Group of Eight major industrial powers met in Washington for talks on Syria and other global crises, with both Britain and France pressing for monitors to verify any eventual ceasefire.

French Foreign Minister Alain Juppe called for the Security Council to seek a "robust observers force" that would verify compliance and "could move freely" without interference from Assad\'s regime.

British Foreign Secretary William Hague warned his government would boost support for Syria\'s opposition and seek further sanctions if Assad does not comply with the ceasefire.

"Our pressure on the regime -- its campaign of murder, torture and oppression -- must be intensified if Kofi Annan has not succeeded," Hague told reporters after the first day of the two-day talks.

On Thursday, Annan is to brief the Security Council by video link from Geneva, in what diplomats said would be key to the world body\'s next steps.

Russia has historically been the top supporter of Assad, and Secretary of State Hillary Clinton had said she would press Russian Foreign Minister Sergei Lavrov over Syria during the G8 talks.

Lavrov said some Arab and Western states had written off Annan\'s peace plan as a failure even before it had gone into effect and called on them to use their influence with the rebels to avoid future unrest.

In Beijing, foreign ministry spokesman Liu Weimin said Syria\'s commitment to the ceasefire "will help ease the tense situation in Syria, and is an important step towards a political solution."

Moscow, which along with China vetoed two Security Council resolutions that would have tightened the screws on Assad, has championed the Annan peace plan but also sought pressure against the Syrian opposition.

Western governments argue a ceasefire alone is not enough and that the Damascus regime must withdraw its troops from towns and cities.

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