SOCHI, Russia - Security is being heightened in the U.S. and abroad due to the opening of the Sochi Winter Olympics.

The Department of Homeland Security is banning all liquids from carry-on luggage for nonstop flights from the U.S. to Russia after a terrorist threat claiming that explosives will be smuggled in via toothpaste tubes.

Olympic teams from around the world have begun to arrive in Sochi with a welcoming committee of Russian warships and military choppers patrolling the sea and sky.

As athletes arrived at their hotels, many released pictures of unfinished hotel rooms.

The head of the Sochi Games says in spite of the unfinished living quarters, the athletes village is the safest place in Sochi, and they are taking several security measures to ensure the well-being of all participants.