BEIRUT (AP) — The latest on the conflict on Syria and the agreement reached on Russia-led talks in Kazakhstan (all times local):

5:35 p.m.

Syria's rebels have expressed their reservations over a Russia-backed "de-escalation zones" deal and are protesting Iran's role in guaranteeing the agreement.

The deal was signed on Thursday by Turkey, Iran and Russia during the Syria cease-fire talks in Kazakhstan. Russia and Iran back the Syrian government while Turkey backs the opposition forces.

Osama Abo Zayed, a spokesman for the Syrian military factions attending the talks in the Kazakh capital, Astana, says the zones raise "a number of questions."

He says Moscow, a major ally of the Syrian government, still has no answers of how to deal with any violations from its ally Damascus or from Iran, which has a number of fighters on the ground in Syria on the government's side.

Abo Zayed says the rebels oppose a role for Iran as a guarantor. The opposition accuses Shiite-majority Iran of fueling the sectarian nature of the Syrian conflict, now in its seventh year.

The rebel factions had said in a statement that any cease-fire must cover all of Syria.

5:05 p.m.

Turkey's foreign ministry has welcomed an agreement signed in Astana, Kazakhstan, to set up "non-conflict zones" in Syria.

The ministry says in a statement on Thursday that the agreement noted efforts to "end all use of weapons, including by aircrafts between clashing parties" and ensure the flow of humanitarian aid.

It says the deal entailed "non-conflict zones" in the whole of Idlib province, parts of Lattakia, Aleppo and Hama provinces, and also parts of Homs province and the Damascus suburb of Eastern Ghouta. It would also apply to areas of Daraa and Quneitra provinces.

Turkey, Russia and Iran are acting as guarantors to the agreement.

The ministry says Turkey will continue its efforts to ensure that the current cease-fire holds so that a political solution can be facilitated.

Syrian opposition delegates walked out of the conference hall as officials from the three guarantor nations signed the deal.

5 p.m.

The head of Russia's delegation to Syrian talks in Kazakhstan says an agreement for setting up four "de-escalation zones" in war-torn Syria will go into effect on Saturday and the Syrian air force is expected to hold its flights over those areas.

Speaking at a press conference in the Kazakh capital of Astana, Alexander Lavrentyev said on Thursday that the Syrian government will abide by the agreement unless attacks are carried out by rebel groups in those areas.

He says Turkey, Iran and Russia have agreed on the possibility of allowing international observers in case there is "unanimity" on that.

3:30 p.m.

Turkey, Iran and Russia have signed an agreement calling for the setting up four "de-escalation zones" in war-torn Syria in the latest attempt to reduce violence in the Arab country.

But as officials form the three countries that back rival sides in the conflict signed the agreement on Thursday at the Syria cease-fire talks in Kazakhstan, some members of the Syrian opposition delegation shouted in protest and walk out of the conference room in Astana, the Kazakh capital.

The opposition has protested Iran's participation at the conference, accusing it of being a party in the war that's killed some 400,000 people.

The Kazakhstan agreement calls for setting up four zones in northern, central and southern Syria. However, no details were provided about how violence will be reduced in these areas.