Sochi Olympics: US warns of toothpaste bombs on Russia flights

On the eve of Sochi Olympic Games, the US has warned American and foreign airlines that terrorists could try to conceal explosives in toothpaste or cosmetic tubes on Russia-bound flights.

The chairman of the US House Homeland Security Committee Michael McCaul said the Department of Homeland Security issued a bulletin to airlines flying into Russia warning of the potential threat.

The bulletin indicated that US officials believed the explosives might be used during flights or smuggled into the Russian city of Sochi, where the Winter Olympics is being held from February 7 to 23.

A US law enforcement official told CNN that the cause for the Homeland Security alert was specific to the imminent start of the games.

Another official emphasised there was no known threat to the US, but the notice to American and international air carriers is based on new intelligence information.

"It's real. It's real and we got very good information. It's based on a credible source. We're taking it seriously. So are other countries. ...," the official said.

In a statement yesterday, the Department of Homeland Security said that, "out of an abundance of caution," it regularly shares relevant information with partners both at home and abroad.

"While we are not aware of a specific threat to the homeland at this time, this routine communication is an important part of our commitment to making sure we meet that priority," it said.

"As always, our security apparatus includes a number of measures, both seen and unseen, and DHS will continue to adjust security measures to fit an ever evolving threat environment," it said.

Security at the February 7-23 Games has been a major concern for the US following two deadly December suicide attacks in the southern Russian city of Volgograd.

Russian transportation officials have banned liquids in airline carry-on luggage ahead of the games, according to a report from the Russian news agency RIA Novosti.

Terrorism experts say that airlines continue to be a target of terrorists wishing to make a spectacular impact with an attack. The focus since 2001 has shifted from hijackings to bombs, especially those that might be hidden in luggage.

For instance, a failed attempt to blow up an overseas flight heading to Detroit on Christmas Day in 2009 involved a bomb concealed in a passenger's underwear.

Shortly after 9/11 a man was convicted of trying to blow up a transatlantic flight with explosives hidden in his shoes.