In recent weeks Syrian government forces backed by Russian air-power have been retaking large swathes of territory on the Syrian Golan Heights from rebel groups along the Israeli border.
"Bombardments have also hit areas in [neighbouring] Deraa province".
Syrian leader Bashar al-Assad continues to wage a campaign to reclaim control of southern Syria, with military support from Russian Federation, triggering the migration.
"Buses began moving from the gathering point towards the edge of the city to be searched", said Mr Abdel Rahman.
The monitor said an estimated 1,400 people were expected to be evacuated on Sunday.
Moscow is concerned by a possible military escalation between Iran and Israel and is doing everything possible to prevent a conflict between them, Russian Ambassador to Iran Levan Dzhagaryan said in an interview with Russian daily Kommersant on Wednesday.
An opposition source familiar with the talks said more than 1,500 civilian and rebel prisoners would be released. Rebels there have yet to agree to a reconciliation deal with Damascus.
Iran, which backs Assad against the mainly Sunni insurgents and has expanded its military role in Syria, has long taken an interest in the fate of its co-religionists in the two towns.
"And we get along in Syria too", Trump said.
The convoy was accompanied by a delegation including the United Nations humanitarian coordinator in Syria Ali Al Zaatari and representatives of the International Committee of the Red Cross.
The regime has been battling to oust rebels from the strategic southwestern provinces of Daraa and Quneitra since June 19, with a mix of heavy bombardment, ground attacks and negotiated surrenders.
The government is now in control of more than four-fifth of that province's territory, the monitor said.
By controlling western Daraa's imposing mountaintops, the pro-government forces are effectively isolating rebel positions by using machine gun fire and artillery strikes to cut off the roadways connecting them, the commander added.
A subcommittee in the US Congress discussed on Tuesday the possibility that America would recognize Israel's sovereignty over the Golan Heights.
Syria's southern border is a prized region for almost all stakeholders in Syria's war due to its strategic geographical position bordering both Jordan and the Israel, while also lying in close proximity to Damascus.
The Observatory said it was doubtful that the airfield was being used to store weapons.
Israel, which seized the Golan in the 1967 Middle East War, has given humanitarian aid to Syrian refugees in encampments close to a 1974 Israeli-Syrian disengagement line. Instead, it was a pit stop to provide equipment and food to the Assad regime forces fighting nearby.