The leaflets were dropped over the cities of Rastan and Tallish, which have been bombarded by Vladimir Putin’s warplanes and where Moscow claims 5,000 ISIS and al-Nusra terrorists are based.
Russian-based media claimed a huge ground operation in the area driven by Syrian President Bashar al-Assad’s troops and reportedly backed by Russia from the air and possibly on the ground, including Putin’s special forces unit Spetnatz.
Iranian troops, last week, also reportedly crossed the border from Iraq in a bid to help prop up Assad’s weakened regime.
The warning, aimed at ISIS and al-Nusra fighters, said:
“Don’t make it even worse for yourselves.”
“The Motherland [presumably Syria] is ready to hug you back again.”
“Give up your arms as hundred of other young guys like you have done.”
And another aimed at civilians read: “Co-operate with the army and leave the zone of the special operations for the sake of your own life.”
The pamphlet designed to look like “religious literature” added they can travel through Syrian checkpoints with the leaflet, and the government will provide “shelter, food and medical aid”.
One warning, obtained by Russian website Komsomolskaya Pravda, included a cartoon of an al-Nusra (al-Qaeda in Syria) figurine being wound up by Israel and the United States.
A reporter from the website said: “Very soon the attack of the Syrian army will start.”
Mr Putin’s forces have bolstered their presence ahead of the anticipated ground assault against ISIS and rebel forces fighting Assad’s regime.
On Friday, yet another warship was sent to the Mediterranean by Moscow, days after a battle group arrived in the region after skirting the British coastline.
Among Mr Putin’s fleet in the Mediterranean is the Navy’s flagship aircraft carrier Admiral Kuznetsov and the nuclear-powered Pyotr Velikiy battle cruiser.
The warships are expected to take part in the bombardment of Aleppo – something Moscow has strenuously denied.