The Russian military on Sunday questioned the official US account of the military raid that killed ISIS leader Abu Bakr al-Baghdadi, saying it was not aware of any US military operations in the region.

In a statement, Russian Defense Ministry spokesman Major General Igor Konashenkov said the Russian military “does not have reliable information” on a US Special Operations raid in Syria’s Idlib province, adding: “The increasing number of direct participants and countries that allegedly took part in this ‘operation,’ each one giving completely contradictory details, raises legitimate questions and doubts about its existence and especially the level of its success.”

In a statement that followed the raid, President Trump thanked Russia for its assistance, as well as Turkey, Syria, Iraq and the Syrian Kurds.

Russia maintains a major base in Syria at Latakia. Konashenkov said, however, that the Russian military had observed no strikes by US aircraft in the region.

“Firstly, on Saturday and in recent days no air strikes were made on the Idlib de-escalation zone by US aircraft or the so-called ‘international coalition’ were recorded,” Konashenkov said. “Secondly, we are not aware of any alleged assistance to the passage of American aviation into the airspace of the Idlib de-escalation zone during this operation.”

Konashenkov argued in his statement that Syrian government backed by Russian air power had defeated ISIS, saying that al-Baghdadi��s death “has absolutely no operational significance on the situation in Syria or on the actions of the remaining terrorists in Idlib.”

Russia, which backs the regime of Syrian President Bashar al-Assad, has long argued that the US military has no legal basis to operate in Syria.