BEIRUT (AP) ? A fragile cease-fire brokered by the U.N. took hold in Syria on Thursday with regime forces apparently halting widespread attacks on the opposition, but there were reports of scattered violence and the government defied demands by international envoy Kofi Annan to pull troops back to barracks.
A civilian and a Syrian soldier were reported killed after the 6 a.m. cease-fire deadline, but there was no sign of the normally intense shelling, rocket attacks and sniper fire that have become routine.
If the truce holds, it would be the first time the regime has observed an internationally brokered cease-fire since Bashar Assad's regime launched a brutal crackdown 13 months ago on mass protests calling for his ouster.
However, troops intensified searches at checkpoints, tightening controls ahead of possible large-scale protests Friday called by the opposition and meant to test the regime's commitment to the Annan plan.
There was deep skepticism that the regime would halt its fire for long, given that Assad has broken promises in the past. Also, the regime said Wednesday, on the eve of the truce deadline, that it reserves the right to respond to any aggression, potentially a pretext for breaking the truce.
Annan's plan calls for the deployment of international observers and talks on a political transition once a truce is in place. The initiative has broad international support, including from Assad allies Russia, China and Iran, and is widely seen as the last chance for diplomacy to end the violence. The increasingly militarized uprising has been veering toward an armed insurgency.
Analysts said the apparent halt in government attacks suggests Assad's allies are pressuring him for the first time, after shielding him from international condemnation in the past. Annan has visited Russia, Iran and China to get the broadest possible backing for the plan.
The West and its allies doubt the sincerity of the regime's pledges to comply with the truce plan, which calls on the Syrian government to allow peaceful protests. A prolonged cease-fire could threaten the regime by encouraging large numbers of protesters to flood the streets, as they did at the start of the revolt against the four-decade rule of the Assad clan. The government met those demonstrations with a harsh crackdown, and more than 9,000 people have died since, according to the U.N.
Bassma Kodmani, spokeswoman of the opposition Syrian National Council, said the truce has largely been observed since 6 a.m. Thursday, but that a heavy security presence, including checkpoints and snipers remain.
"There is no evidence of any significant withdrawal," she told reporters in Geneva. "The real test for us today is if people can go and demonstrate peacefully" she added. "This is the real reality check."
The group's leader, Burhan Ghalioun, urged Syrians to demonstrate peacefully on Friday, the day of weekly protests since the uprising began. "Tomorrow, like every Friday, the Syrian people are called to demonstrate even more and put the regime in front of its responsibilities ? put the international community in front of its responsibilities," he said.
Annan is to brief the U.N. Security Council by video conference from Geneva on Thursday afternoon.
Syria's state-run news agency, SANA, said a roadside bomb exploded near a bus carrying soldiers in the northern city of Aleppo, killing one officer.
And the Britain-based Syrian Observatory for Human Rights, an activist group, said a man was shot dead in the central town of Safsafiyeh in Hama province. The group gave no further details, but Mousab Hamadee, an area activist, said troops shot and killed the man who was apparently wanted by the authorities and tried to flee a checkpoint where he was stopped.
Troops opened also fire in several areas in the northern province of Idlib, but there were no reports of casualties, said activist Fadi al-Yassin. Al-Yassin said troops were taking strict measures at checkpoints, asking people to leave the car and then searching them thoroughly. He said lines of cars are stretching for hundreds of meters (yards) at checkpoints.
A grassroots opposition group, the Local Coordination Committees, said regime forces carried out arrests in the Damascus suburb of Maadamiyah shortly after reinforcements entered the area. It also reported anti-regime protests at universities in the southern city of Daraa and the eastern city of Deir el-Zour, and a protest march in the northern village of Tamanaa.
On Tuesday, the regime had ignored a deadline for withdrawing troops from population centers, prompting renewed demands by Annan that forces return to their barracks. Turkish Foreign Minister Ahmet Davutoglu also demanded Thursday that the Syrian troops withdraw, saying that "keeping the cities under pressure is not meaningful."
However, Assad apparently is unwilling to ease control over opposition areas for fear of widespread anti-government protests.
A major test could come on Friday. Since the outbreak of the protests in March 2011, thousands have taken to the streets every week after Friday noon prayers in the mosques.
The military crackdown over the past year succeeded in preventing protesters from recreating the fervor of Egypt's Tahrir Square, where hundreds of thousands of people camped out in a powerful show of dissent that drove longtime leader Hosni Mubarak from power.
The government denies that it is facing a popular uprising, claiming instead that terrorists are carrying out a foreign conspiracy to destroy Syria. In pledging Wednesday to observe the cease-fire, the government set a major condition, saying troops reserve the right to defend themselves if attacked.
Syrian troops have been on a major offensive since late January when they attacked rebel-held areas around the capital Damascus. During the first week of February, Assad's forces began a major campaign to retake the Baba Amr neighborhood in the city of Homs that fell in the hands of the regime in early March.
Since then, Assad's forces have been retaking major rebel-held areas including the city of Idlib as well as many towns around the country. Troops also now control much of the areas that border Turkey, Lebanon, Jordan and Iraq making it more difficult for refugees to leave the country. Despite the regime gains, rebels still held some areas, including spots in the province of Homs, Hama, Daraa.
The White House cautioned Wednesday that the Assad regime has reneged on promises to stop the violence in the past.
"What is important to remember is that we judge the Assad's regime by its actions and not by their promises, because their promises have proven so frequently in the past to be empty," White House spokesman Jay Carney told reporters in Washington.
Western powers have pinned their hopes on Annan's plan, in part because they are running out of options. The U.N. has ruled out any military intervention of the type that helped bring down Libya's Moammar Gadhafi, and several rounds of sanctions and other attempts to isolate Assad have done little to stop the bloodshed.
Saudi Arabia and Qatar have called for arming the rebels, but even if they follow through there is no guarantee that such efforts could cripple Assad's well-armed regime.
In other developments, Turkish Prime Minister Recep Tayyip Erdogan said Turkey could seek NATO's help in case the Syrian troops violate its borders again. Syrian forces opened fire across the Turkish border on Monday, killing two people in a Turkish refugee camp.
Associated Press writers Frank Jordans in Geneva and Selcan Hacaoglu in Ankara, Turkey, contributed reporting.