Terrorists could be trying to place explosives disguised as toothpaste on Russia-bound flights, the US Government has warned.
The Sochi Winter Olympics start in just a day – but an American intelligence official said information suggested terrorists were "specifically targeting flights to Russia."
The US warned airlines flying into Russia for the Winter Olympics could have explosives hidden in toothpaste tubes smuggled on to planes.
The Department of Homeland Security told the BBC the alert affected flights direct into Russia as it prepares for the games in Sochi.
Amidst scenes of chaos reported by international journalists and world-wide condemnation of Russia's anti-gay laws, Vladimir Putin has insisted the country is ready to host the Winter Olympics.
But yesterday he acknowledged the threat from terrorism was real.
Visiting the athletes’ village, he said: “We remember tragic situations which happened in the past during international competitions, including the one in the United States during the marathon. It’s all quite recent."
The toothpaste concern is the latest reported threat against the region, which has dramatically escalated security surrounding the games – creating a "ring of steel".
Fears were raised following two suicide attacks in Volgograd in December, and numerous threats from Islamist militants in the Caucasus region.
Chechen warlord Doku Umarov has urged his followers to use "maximum force" to attack what he called "satanic dances on the bones of our ancestors".
Russian authorities have pledged to make the event the "safest ever".