Russian and Syrian fighter jets have struck the rebel-held city of Idlib on Dec. 1 amid attempts to push back an insurgency that has taken over most of Aleppo, Reuters reported, citing Syrian army sources.

The foreign ministers of Iran and Russia voiced support for Syria on Saturday during a major attack by rebel groups, Iranian state media reported.

Russia's Defence Ministry said its air force had carried out strikes on Syrian rebels in support of the country's army, Russian news agencies reported on Saturday, amid an advance by forces opposed to Syrian President Bashar al-Assad.

Diminished support for the Syrian government from Iran, Hezbollah and Russia enabled opposition forces to take the initiative and seize new territory.

Syrians are generally repelled by extreme religious rhetoric. As jihadist groups came to dominate the rebellion after pro-democracy demonstrations were crushed after the first year or so of war after 2011, many Syrians either stayed neutral or sided reluctantly with the regime because they feared the murderous jihadist ideology of Islamic State.