UN-Arab League envoy Kofi Annan said a ceasefire in Syria appeared to be holding on Thursday.
Annan added, however, that the Syrian government must carry out a withdrawal of troops and heavy weapons from cities, which is included in the plan. United Nations chief Ban Ki-moon, meanwhile, said plans were being drawn up to send observers to Syria, starting with the dispatch of a UN peacekeeping general as early as Friday. "We are working to send an observer team as promptly as possible," Ban told a news conference in Geneva."The world is watching however with sceptical eyes," he added, since previous promises made by the Syrian regime "have not been kept."
Renewed bloodshed on Thursday killed at least four people, putting to the test the hard-won ceasefire plan. The opposition said regime forces killed three civilians and arrested dozens more in defiance of its undertaking to Annan to halt all military operations and withdraw troops from towns and cities by 6 a.m.
The opposition Syrian National Council (SNC) said the epicentre of Thursday's bloodshed was the central region of Hama. Spokeswoman Basma Qodmani called for peaceful demonstrations across Syria to test the government's readiness to accept public shows of dissent. "The real test will be if there is shooting or not when people demonstrate," she said.
State media charged that it was the opposition who were jeopardising the long-awaited truce, accusing rebel fighters of bombing a bus ferrying troops to their base in Syria's second-largest city Aleppo.
"An armed terrorist group used an explosive device to target a bus transporting officers and non-commissioned officers to their unit in Aleppo. It killed a lieutenant colonel" and wounded 24 others, state news agency SANA said.
The interior ministry urged tens of thousands of people who fled the violence both inside and outside the country to return home and offered an amnesty to opposition gunmen without "blood on their hands."
The rebel Free Syrian Army, for its part, insisted it was "100 percent committed" to the ceasefire in a conflict which monitors say has killed more than 10,000 people since March last year.
Hours before the deadline expired, the military unleashed a lethal offensive against protest centres, killing 25 civilians on Wednesday, including 10 in the rebel stronghold of Rastan, the Syrian Observatory for Human Rights said.
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.