Russia, Turkey, and Iran have signed a memorandum calling for the establishment of safe zones in Syria during peace talks in Kazakhstan, but some Syrian opposition representatives walked out in protest.
The agreement was signed on May 4 by representatives of the three countries sponsoring the negotiations in Astana, the Kazakh capital.
The memorandum calls for setting up four "deescalation zones" in various parts of Syria, where forces of President Bashar al-Assad's government are fighting rebels in a war that has killed some 400,000 people since 2011.
Part of the Syrian opposition delegation left the talks in protest at Iran signing the memorandum. Iran and Russia have backed the Syrian government throughout the war, while Turkey supports its opponents.
"We do not accept Iran's involvement as a guarantor country," a member of the opposition delegation shouted while Kazakh Foreign Minister Kairat Abdrakhmanov was speaking.
The opposition has been angered by Iran's participation at the conference, accusing it of being a party in the war.
