The Syrian government must end year-long deadly violence and open talks with its opponents, an Arab summit draft resolution said, also urging the fractured opposition to unify its ranks.

The document was prepared for Arab officials gathering in Baghdad for a series of meetings that began on Tuesday and will culminate in a summit of regional leaders on Thursday.

The draft resolution, a copy of which was obtained by AFP, urges the "Syrian government and all opposition factions to deal positively with the (UN-Arab League) envoy (Kofi Annan) by starting serious national dialogue."

Talks should be based on an Arab League plan "and the decision of the UN General Assembly," it says.

The draft resolution also calls on the Syrian opposition "to unify its ranks and prepare ... to enter into serious dialogue (with the regime) to achieve the democratic life which is demanded by the Syrian people."

"The Syrian government should immediately stop all actions of violence and killing, protect Syrian civilians and guarantee the freedom of peaceful demonstrations for achieving demands of the Syrian people," said the text.

It adds that "the massacre committed by the Syrian military and security forces against civilians in Baba Amr... can be considered a crime against humanity."

The neighbourhood of Baba Amr in the flashpoint central Syrian city of Homs was overrun by regime forces on March 1 following a month-long relentless assault to root out rebels.

Hundreds of people, many of them civilians, were killed in the fighting, according to rights groups.

The Arab League on January 22 asked the United Nations to support a new plan for resolving the crisis in Syria that sees Assad transferring power to his deputy and a government of national unity within two months.

On February 16, the UN General Assembly demanded an immediate halt to the crackdown in a strongly-worded resolution adopted by a 137-12 vote.

The Baghdad summit is the first of its kind to be hosted by Iraq in 20 years.