The Russian defence ministry denies accusations that its warplanes were behind one of the most intense bombings in the city since the ceasefire went into effect in late December.
Several airstrikes have hit the opposition-held northwestern Syrian city of Idlib, killing at least 15 people, Syrian activists and paramedics said on Tuesday.
The latest airstrikes in Idlib are among the most intense since a ceasefire brokered by Russia and Turkey went into effect in late December. Idlib, the capital of a province of the same name, has become a key base for rebels and insurgents battling the Bashar al-Assad regime.
Russia, an ally of the Syrian regime, was accused of being behind the strikes. However, Russia's defence ministry, cited by Interfax news agency, refuted media reports which said Russian planes had bombed Idlib.
Activist groups gave varying death tolls – not uncommon in Syria, as six years of war have resulted in limited access and significant destruction.
The Britain-based Syrian Observatory for Human Rights says 26 people were killed, including 10 civilians.
The Civil Defence or White Helmets in Idlib say 15 bodies were pulled from under the rubble and 30 wounded were taken for treatment.
Fight for al-Bab
The SOHR reported that the regime and its allies advanced against Daesh in al-Bab, in north Aleppo province on Monday.
The advances meant the regime forces had reinforced their siege of the strategic town, cutting off a supply route between al-Bab and Daesh strongholds of Raqqa, Deir Ezzor and Aleppo, the observatory said.
Regime forces have been advancing on al-Bab from the southwest, while Turkish-backed Free Syrian Army forces have been advancing from the north.