As the Olympic Games get underway in Sochi today security officials are on alert for a new potential terror threat.
The US Department of Homeland Security issued an advisory called a "tear-line" bulletin late Wednesday warning airlines that terrorists may have found a new way to smuggle explosives onto airplanes using toothpaste or skin care products.
Sources say the worry is teams of operatives could bring bomb-making components on board an airliner and then assemble an improvised explosive device while the plane is in flight.
The potential threat is aimed at Russia and the Olympics and the security warning is for carriers flying from international cities to Russia.
Russian security forces are everywhere in Sochi. They have built a so-called "ring of steel" to protect the Olympic venues and visitors.
Russian Olympic committee president Alexander Zhukov says:
"We have taken all the necessary measures to ensure safety."
"This includes deploying more than 40-thousand police and soldiers."
A federal official tells CBS news, the alert originated after the arrests of Chechen female suspects in Austria and France.
Terrorists carried out twin suicide bombings in Volgograd not far from Sochi in December. And Muslim militants have vowed more attacks during the games.