About 10 Syrian rebel groups announced Monday they were suspending talks about planned peace negotiations this month in the Kazakh capital Astana, due to "violations" by Damascus of a four-day old truce.

"As these violations are continuing, the rebel factions announce... the freezing of all discussion linked to the Astana negotiations," they said in a joint statement, referring to talks planned for late January organised by Russia, which supports the Syrian regime, and Turkey which backs the rebels.