A Russian airstrike left at least 23 people dead in the rebel-controlled Idlib province in Syria, the BBC Russian Service reported Tuesday, citing the London-based Syrian Human Rights Watchdog.
The airstrike is considered to be the largest since the signing of a cease-fire agreement in February.
One of the shells allegedly hit a hospital, killing seven children, watchdog head Rami Abdulrakhman claimed, and said the number of fatalities could rise.
The Russian Defense Ministry has officially denied the accusations, saying that Russia did not perform any military tasks in Idlib and recommended adopting a ?€?critical attitude to any horror stories,?€? said ministry representative Igor Konashenkov.
As Russia maintains that its military operations in Syria are aimed only at terrorists, the Syrian opposition testifies to the contrary, claiming that Russia is mainly attacking rebel groups supported by the West.
The cease-fire agreement that came into force on Feb. 27 does not apply to extremist groups, including the Islamic State.
Idlib is believed to be the base of several rebel groups, such as the al-Qaida affiliate, al-Nusra Front, the BBC reported.
The Islamic State and the al-Nusra Front are terrorist organizations banned in Russia.