MOSCOW, December 27. /TASS/. Terrorists of the Islamic State group (outlawed in Russia) are undergoing training at the US Al-Tanf military base southeast of the eponymous Syrian city, the chief of the Russian General Staff, Army Gen. Valery Gerasimov, said on Wednesday.

"This base in Syria’s south is located within an area with a radius of 55 kilometers. It lies on the border of Syria, Jordan and Iraq. According to space intelligence and other sources, groups of militants stay there. De-facto, they train there," the official said in an interview with the Komsomolskaya Pravda daily.

According to Gerasimov, militant groups are also present in the Al-Shaddadi camp in the country’s northeast, where another US military base is also located. Those militants are, in fact, members of the Islamic State, but their groups assume different names, he added.

"Their task is to destabilize the situation. We know that about 400 people from the Shaddadi camp left for the Al-Tanf region. When the main forces of the ISIL [the former name of the Islamic State group] were defeated, they attempted to destabilize the situation by launching an offensive from the eastern bank of the Euphrates River, but sustained serious losses," the Russian general said,

According to the Russian General Staff’s estimates, about 750 militants currently stay at Shaddadi and some 350 - in Al-Tanf.

Gerasimov added that Pentagon has so far failed to offer any explanation for keeping is military presence at the Al-Tanf base after the defeat of the Islamic State.

"So far, their answers have been ambiguous," he said.

Currently, the entire perimeter of the 55-kilometer zone of the Al-Tanf base is blocked by the Syrian troops.