Russia claimed that a US Navy P-8 aircraft flew overhead during the attack, drawing a link between the US military and the militant drone attack, however multiple US defense officials told CNN that a P-8 was not operating in the area during the incident and has not flown in the area for some time.
The Russian Ministry of Defense issued a statement Monday saying that 10 "assault drones" had attempted to attack Khmeimim Air Base, the Russian military's primary air base in Syria. The statement said three additional drones had tried to attack the Russian naval facility at Tartus.
Russian troops were able to intercept the drones using electronic warfare jamming and Pantsir-S1 anti-aircraft missiles, according to the statement, which also said that no casualties or damage to Russian equipment resulted from the attack.
The Russians said an analysis of the downed drones found they were using a "modern GPS guidance system," adding that the drones used technology that may have been supplied by "countries with high-technological capabilities of satellite navigation and remote dropping control of professionally assembled improvised explosive devices."
The statement said the drones "carried explosive devices with foreign detonating fuses," adding that the "usage of strike aircraft-type drones by terrorists is the evidence that militants have received technologies to carry out terrorist attacks."
The Pentagon declined to comment on the nature of the drones involved in the attack on the Russian facilities but did note that US and coalition troops fighting ISIS had faced "commercially available" drones used by the terror group which are "widely available, easy to control and certainly do not require significant technical expertise."
The Russian Ministry of Defense issued a statement Tuesday slamming the Pentagon's comments.
The Russians also implied that the US may have had a role in the recent attack, saying the technology used in the drone attack "draws attention to the fact that the US Navy Poseidon intelligence aircraft was patrolling between Tartus and Khmeimim over four hours at the altitude of 7,000 meters during terrorists' attack."
The US military rejected the accusation, calling it "utterly irresponsible."
"We do not discuss the disposition of intelligence platforms. Any suggestion that that US or coalition forces played a role in an attack on a Russian base is without any basis in fact and utterly irresponsible," Pentagon spokesman Maj. Adrian Rankine-Galloway said.
The US Navy did not have P-8 surveillance aircraft operating in the area during the time that the Russians claimed it was there and a P-8 aircraft has not operated in the area for some time, three US defense officials told CNN Wednesday.
The spat comes as Russian facilities in Syria have come under multiple attacks.
Less than a week prior to the drone attack, unidentified militants launched a New Year's Eve mortar attack on Khmeimim Air Base that damaged several aircraft and inflicted casualties on military personnel, according to Russian media outlets.
A US defense official confirmed the details of the damage to CNN.
That attack came less than a month after Russian President Vladimir Putin visited the base
to mark the Russian military's success in backing the regime of Bashar al-Assad.
While Putin had announced that a "significant part of the Russian military contingent" would withdraw from Syria, he said the Russians would continue to maintain the two bases.
A spokesman for the Kremlin defended the Russian military's ability to guard against attacks during a Tuesday conference call with members of the press.
"The military infrastructure that remains at the bases in Khmeimim and in Tartus have all the necessary capabilities to combat these occasional terrorist attacks, which unfortunately will continue," Dimitry Peskov told reporters.