Hundreds of rebels and their families have boarded buses to leave a besieged opposition-held neighbourhood of the Syrian capital Damascus, according to state TV and opposition activists.
They are heading for rebel-held areas in the country's north under an agreement between the warring sides in the country.
The development is the latest in a series of population transfers in the war-torn country over the past year.
However, the evacuation of some 1,500 people from the north-eastern Barzeh neighbourhood in Damascus is the first in this area.
It is also the first since Russia, Turkey, and Iran agreed on Friday to enforce a ceasefire between government and opposition forces in four areas in Syria.
Barzeh came under siege last month, after government forces captured a major road near the area separating it from rebel-held eastern suburbs of Damascus.
Over the past months, tens of thousands of people living in besieged areas around Damascus, Homs, and Aleppo - Syria's largest city - have surrendered after prolonged sieges in exchange for safe relocation to opposition-held areas elsewhere in the country.
The Britain-based Syrian Observatory for Human Rights said hundreds are expected to leave Barzeh, with around 1,500 expected to leave on Monday and more in the coming weeks.
Mazen al-Shami, an opposition activist based near Damascus, said the opposition fighters and their families are boarding the buses in Barzeh to head to the rebel-held north-western province of Idlib. He posted a photo online showing fighters with their automatic rifles standing near buses.
The government-controlled Syrian Central Military Media said some 500 fighters will head to Idlib, while dozens of other Barzeh residents plan to stay, apparently benefiting from an amnesty offered to opposition fighters who decided to return to normal civilian lives.
Syrian state TV said some 60 buses and ambulances of the Syrian Arab Red Crescent were in Barzeh for the evacuations.
Some opposition activists have criticised the population movements as "forced displacement".
Last month, UN Secretary-General Antonio Guterres warned that the forced movement of civilians could constitute a war crime.
He said the UN has repeatedly expressed concern at local evacuation agreements that follow the decimation of an area and result in the forced displacement of civilians.
The UN chief reminded Syria's government and opposition groups that forced displacement of civilians is "permissible solely in order to guarantee their security or for imperative military necessity". Otherwise, forced movements are prohibited and may be war crimes, he said.
As for the Russia-Iran-Turkey ceasefire deal, there are still questions about how it will be enforced.
Russia and Iran, which support the government, and Turkey, which backs the rebels, may deploy armed forces to secure the four so-called "de-escalation zones", in what would amount to unprecedented coordination between the three countries.
Even if the agreement is enforced, it is unlikely to end the conflict. Despite several rounds of UN-mediated negotiations in Geneva, the government and opposition remain at odds over President Bashar Assad's future role in Syria.
The United States is not party to the de-escalation agreement, and the Syrian government and opposition have not signed on to the deal. The armed opposition is critical of the agreement and has demanded a national ceasefire instead.
Later, Syria's foreign minister said there will be no international forces under UN supervision as part of the deal struck by Russia, Iran and Turkey.
Walid al-Moallem told reporters at a news conference in the Syrian capital that the agreement signed in the Kazakh capital, Astana, stipulates for the deployment of "military police" at observation centres in four so-called de-escalation zones.
He did not elaborate on who the military police would be but appeared to be inferring to Russian observers already on the ground in Syria.
Mr al-Moallem reiterated his government's commitment to the Astana deal but said it is "premature" to talk about whether it will be successful.
He said "there are still logistical details that will be discussed in Damascus and we will see the extent of commitment to this agreement".
He added that militants must be purged out of safe zones envisaged by the agreement.
He said armed Syrian opposition groups must separate themselves from extremist groups such as al Qaida's Syria branch. Mr al-Moallem said "it is the duty" of these armed groups to force the militants from their areas so that they can become safe.
He added that it is also the duty of the agreement's guarantors to help the armed factions push the militants from their areas.
Mr al-Moallem said the Syrian army's military priority now is to liberate areas in eastern Syria near the Iraqi border held by the Islamic State group.