Outbursts of fighting threatened to undermine a fragile ceasefire that took effect in Syria on Friday after Bashar al-Assad’s regime and the main rebel force agreed to down arms for a four-day Muslim holiday. The Syrian Observatory for Human Rights said the ceasefire had “collapsed” with fighting in several regions, but that violence was still at unusually low levels. And there were no indications yet from either the Assad regime or the main rebel Free Syrian Army (FSA) that they were abandoning the truce. “The ceasefire has collapsed in several regions of Syria but there is still less violence and fewer victims than usual,” observatory director Rami Abdel Rahman told reporters. He said fighting was taking place in various parts of the country, including in the capital Damascus, in the city of Homs and near the Wadi Deif military base in the northwest. At least five people were dead. Regime forces and the FSA said on Thursday they would follow UN-Arab League peace envoy Lakhdar Brahimi’s call for the temporary ceasefire, but both reserved the right to respond to any aggression. If the ceasefire holds it would be the first real breakthrough in halting – even temporarily – the violence that has plagued Syria during the 19-month conflict rights groups say has killed more than 35,000 people. The international community has piled pressure on all sides to stand by the truce and a senior Arab League official said on Friday it appeared to be holding. Ahmed Ben Hilli, the League’s deputy secretary general, told AFP the truce was “being respected according to initial indications” and that it could be followed by a longer ceasefire and a proposal to deploy UN peacekeepers. After clashes overnight, the ceasefire took hold with morning prayers kicking off the Eid al-Adha feast at the end of the hajj pilgrimage, and state television showed Assad attending a Damascus mosque, smiling and chatting with worshippers. The ceasefire was also tested as security forces opened fire at anti-regime protests that followed the prayers. The protests took place in Damascus and its suburbs, in Aleppo, in the northeast in Deir Ezzor and Raqa and at several towns in the southern Daraa province, according to activists and the observatory. At the town of Inkhel in Daraa, police used gunfire to disperse protesters, injuring three people, said the observatory, which relies on a network of activists, medics and lawyers on the ground for its information. General Mustafa al-Sheikh of the FSA said the rebels considered the protest crackdown a violation of the ceasefire but were not planning to respond. “Preventing demonstrations by opening fire is a violation of the ceasefire. But we are showing more restraint than the regime because for the moment we want to give the ceasefire a chance,” he told reporters by telephone from Turkey. In Aleppo, residents were sceptical the truce would hold but the relative lull saw families returning to bombed out homes on the front line to recover possessions and inspect the damage. “He’s a cheater,” spat Abu Ali, an electrician and father of four, when asked if he believed Assad would abide by the truce. “Nobody believes him. He’ll give you a promise then do whatever he wants,” he snapped en route to collecting his children’s winter clothes from his home in Salaheddin, a bastion of rebel support in Aleppo heavily damaged by fighting. The ceasefire was backed this week by the United Nations Security Council and a spokesman for UN chief Ban Ki-moon said Thursday that “the world is now watching” to ensure both sides stick by their commitment. The conflict began in March last year with pro-reform protests inspired by the Arab Spring, but is now a civil war pitting mainly Sunni rebels against Assad’s regime dominated by his minority Alawite sect, an offshoot of Shiite Islam. The United States also expressed hope the ceasefire will be respected. “What we are hoping and expecting is that they will not just talk the talk of ceasefire, but that they will walk the walk, beginning with the regime,” US State Department spokeswoman Victoria Nuland said. The Syrian army said it would cease military operations from Friday morning to Monday, but warned it would react if “armed terrorist groups” carry out attacks or reinforce their positions, or if fighters cross into the country. An April ceasefire announced by Brahimi’s predecessor, former UN secretary general Kofi Annan, failed to take hold. Heavy fighting had continued Thursday on the eve of the holiday, with rebel forces moving into new areas of Aleppo, including Kurdish and Christian districts. At least 135 people were killed in fighting Thursday, the observatory said, including 65 civilians, 41 soldiers and 29 rebels. Brahimi has stressed the importance of even a temporary lull in the fighting, saying: “If we succeed with this modest initiative, a longer ceasefire can be built” that would allow the launch of a political process.