Europe is braced for three million migrants streaming out of Syria to flee a devastating new air and ground offensive by Russia and the Assad regime.

Russian warships fired 26 cruise missiles yesterday from the Caspian Sea into Syria as President Assad’s ground troops launched an all-out assault on the rebels. The missiles, the first to be used by Russia in a war, travelled 900 miles over Iranian and Iraqi airspace before hitting targets in northern Syria.

Both Brussels and Turkey have warned that President Putin’s deepening involvement in the four-and-a-half-year Syrian conflict will provoke a new exodus of refugees. Donald Tusk, president of the EU Council, has now warned MEPs that “according to Turkish estimates, another three million potential refugees may come from Aleppo