Russian President Vladimir Putin's spokesman denied allegations that the country's warplanes struck a hospital in northern Syria amid growing concerns over Kremlin’s airstrikes in the war-torn region. Syrian Observatory for Human Rights said Monday that Russian warplanes targeted the hospital in Idlib province, killing nine people.

Dmitry Peskov told reporters Tuesday that only official announcements from the Syrian government should be believed, adding that there is no evidence to back the claims. Peskov also rejected claims made by Turkey that Russia committed a war crime in Syria by attacking civilians.

"We categorically do not accept such statements, the more so as every time those making these statements are unable to prove their unfounded accusations in any way," Peskov told reporters, according to Reuters.

On Monday, missile attacks on several medical facilities and a school in Syria killed at least 23 people.

The hospital in Maarat al-Numan was hit by four missiles, minutes apart, and the quick succession "leads us to believe that ... it wasn't an accidental attack, that it was deliberate," Sam Taylor, a spokesman for Doctors Without Borders operations in Syria, said, according to the BBC.

Turkish Prime Minister Ahmet Davutoglu said Monday that Russian missiles had hit the buildings, leaving many civilians, including children, dead. Turkey's foreign ministry accused Russia of carrying out an "obvious war crime."

Russia has claimed that its airstrikes in Syria are aimed at destroying terrorist strongholds, including that of the Islamic State group. However, several Western countries believe that the offensive is targeted at eliminating opposition groups fighting the regime of Syrian President Bashar Assad, a close ally of Russia.