They aren't shooting at anyone - yet. But even though the guns in Syria have fallen silent for a few hours, the terms of the UN cease fire agreement are not being implemented by President Assad.

The truce calls for the Syrian army to pull out of towns and cities where they have been relentlessly shelling civilian neighborhoods for weeks. That hasn't happened, which leads many experts to believe that the cease fire won't last.

Reuters:

Syrian troops held their fire in the hours after a U.N.-backed ceasefire took effect at dawn on Thursday, casting a silence over rebellious towns they had bombarded heavily in recent days.

But streets in troubled towns remained nervously empty. An exile opposition spokeswoman said three people had been killed during the morning by security forces, and dozens more arrested.

But the lull did little to convince opposition activists and Western powers of President Bashar al-Assad's good faith in observing a peace plan agreed with international envoy Kofi Annan. In defiance of that deal, Syrian troops and tanks were still in position inside many towns, activists told Reuters.

A report on state media that a "terrorist" bomb blasted an army bus and killed a senior officer in Aleppo after the truce began raised a possibility troops will keep a pledge to hit back. State media also reported a bomb wounding officers near Idlib and a ruling party member shot dead in Deraa in the south.

The Syrian government bars access to most independent media.

The exile opposition called the ceasefire "only partially observed" due to the army's failure to leave the streets and its leader urged a renewal on Friday of peaceful protests, which have been subdued of late by fear. But he warned those who might take part that they could expect government forces to open fire.

The Interior Ministry urged rebels to surrender, promising to free those who had not killed, and broadcast an appeal to the thousands who fled battered cities like Homs and Hama to return from the havens they found in Turkey, Lebanon and within Syria.

Most of those refugees will not come home until Assad is gone. And since the rebels and Syrian National Council won't talk to Assad or his government, there is little chance of that happening soon.

Assad will use the cease fire for resupply of his troops and perhaps a reorganization of his battle plan. If the truce lasts more than a few hours, most observers will be surprised.