The attacks drew an increasingly angry response from the West.
The US-led coalition that is waging its own air war against IS called on the Russians to halt strikes on targets other than IS.
“We call on the Russian Federation to immediately cease its attacks on the Syrian opposition and civilians and to focus its efforts on fighting ISIL,” said the coalition, which includes the US, major European powers, Arab states, and Turkey.
“We express our deep concern with regard to the Russian military build-up in Syria and especially the attacks by the Russian air force on Hama, Homs and Idlib since yesterday which led to civilian casualties and did not target Daesh,” it said.
ISIL and Daesh are both acronyms for IS, which has set up a caliphate across a swathe of eastern Syria and northern Iraq.
In Syria, the group is one of many fighting against Russia’s ally, president Bashar al-Assad.
Washington and its Western and regional allies say Russia is using it as a pretext to bomb other groups that oppose Assad.
Some of these groups have received training and weapons from Assad’s enemies, including the US.
Russian president Vladimir Putin held frosty talks with France’s Francois Hollande in Paris, Putin’s first meeting with a Western leader since launching the strikes two days after he gave an address to the UN making the case to back Assad.
Syrian foreign minister Walid al-Moallem says his country will participate in UN-led working groups toward a third round of Geneva talks on the fate of the country.
Al-Moallem addressed a UN gathering of world leaders as the international community scrambled to respond to Russia’s new airstrikes in his country.
He stressed that the working groups proposed by the UN’s special envoy on Syria, Staffan de Mistura, are non-binding.
Al-Moallem added that airstrikes alone will not be successful against IS unless they are co-ordinated with the Syrian government.
Warplanes were seen flying high above the area, which is held by anti-Assad rebels but has no significant presence of IS fighters.
A Russian air strike on Thursday destroyed a mosque in the town of Jisr al-Shughour, captured from government forces by an alliance of Islamist insurgents earlier this year, activists said.
Moscow said its latest strikes had hit 12 IS targets, but most of the areas it described were in western and northern parts of the country, while IS is mostly present in the east.
As Hollande hosted Putin in Paris, both men looked stern and frosty-faced in the yard of the Elysee palace, exchanging terse handshakes for the cameras.
Hollande laid out France’s conditions for supporting Russian intervention, which include a halt to strikes on groups other than IS and al-Qaida, protections for civilians and a commitment to a political transition that would remove Assad.