Syria's fragile truce is in its third day, with the UN Security Council expected to vote any time on a resolution authorizing the deployment of the first wave of UN military observers to monitor the cease-fire.
Security Council members met behind closed doors for several hours on April 13 to discuss rival drafts by the U.S., its European allies, and by Russia.
International envoy Kofi Annan's spokesman, Ahmad Fawzi, told a news conference in Geneva that an advance team of "around 10 or 12" observers is "standing by to board planes and to get themselves on the ground as soon as possible" after the expected vote.
Activists say Syrian troops shelled two rebel-held neighborhoods in the central city of Homs overnight.
The Britain-based Syrian Observatory for Human Rights says the bombardment lasted for about an hour, with no reports of casualties.
Based on reporting by dpa, AP, and Reuters