Members of the United Nations Security Council have finalised a new draft of a resolution authorising a team of observers to monitor the ceasefire in Syria.
A small advance team was ready to travel to Syria if the Security Council votes in favour of the resolution on Saturday.
It would be followed by a second, more substantial force of UN monitors.
The ceasefire, negotiated by UN and Arab League envoy Kofi Annan, required Government troops to pull back.
Mr Annan's spokesperson, Ahmad Fawzi, says it is worrying that tanks and artillery are still in Syrian cities.
A human rights group and a resident activist say Syrian forces shelled two central districts in the battered city of Homs on Friday night in violation of the ceasefire.
The resident says there was shelling in the old part of the city, in Jouret al-Shiyah and al-Qaradis. He says he heard eight shells fall.
The British-based Syrian Observatory for Human Rights said that shelling had wounded several people.
Several people were reported to have been shot dead during demonstrations after Friday prayers in various parts of Syria, where a ceasefire came into effect on Thursday morning.
Reports say security forces fired into the air to disperse crowds as they left their mosques in several locations. Two people were killed in the city of Hama.
Two other people were shot dead in the town of Nawa, in the southern province of Deraa, while a fifth died in the town of Salqin, in the north-western province of Idlib.
The Sana news agency reported said an army officer was killed and 24 others wounded when a bomb exploded next to a military bus in Aleppo, and that a Baath Party official was shot dead in al-Mazarib, in Deraa province.
The ceasefire came into effect at 6am on Thursday.
Meanwhile, Turkey has begun accepting international aid to help share the cost of caring for nearly 25,000 people who have crossed the border from Sryia.
Jordan is also housing almost 100,000 refugees.