Three countries backing different sides in Syria's war have agreed to set up "safe zones" in the country. Russia's plan for de-escalation zones was backed by Iran at talks in Kazakhstan. <br/><br/>Both countries support Syrian president Bashar al-Assad. Turkey, which supports rebel groups, also agreed to act as a guarantor.<br/><br/>But some delegates from the rebel forces angrily rejected the plan. As the three countries were invited to sign the document yesterday in the Kazakh capital, Astana, rebel delegates angrily shouted that they did not accept it and walked out. Reporters at the talks said the rebels were unhappy about Iran's involvement in the deal as a guarantor. <br/><br/>Safe zones would be established in rebel-held territory in the north-western province of Idlib, in parts of Homs province and in the opposition enclave of Eastern Ghouta near Damascus