02/06/2014 07:13 EST | Updated 04/08/2014 05:59 EDT

Sochi Olympics under tight security as concerns grow

As the Sochi Olympics open, the Russian government says it's doing everything possible to ensure safety at the Games — even as the U.S. warns airlines that enemies may try to smuggle toothpaste tubes carrying explosives into Russia.

"We can guarantee the safety of the people as well as any other government hosting a mass event [can]," said Russian Deputy Prime Minister Dmitry Kozak on Thursday, one day before the opening ceremony.

While the Winter Games officially open Friday, some qualifying events are already underway.

Security concerns have been at the forefront of the Sochi Games for months. They were renewed this week when the U.S. Homeland Security Department warned airlines flying to Russia that toothpaste may be the weapon of choice for people targeting the Games this year.

Kozak said Russia is taking steps to collaborate with nations to build a database on potential terrorists.

"There is no reason to believe Sochi, in Russia, is under more threat than any other city in the world," he said.

Kozak says the fear of terrorism is always present at big sporting events, in Russia or anywhere else. But he also believes "the level of fear should be lower" surrounding the Sochi Games.

Meanwhile, the chief organizer of the Sochi Olympics says a record number of world leaders are coming to the Games.

Record list of leaders

Dmitry Chernyshenko said 65 heads of state and government and international organizations are expected to attend Russia's first Winter Olympics.

He says it's a record for Winter Games and three times the number of leaders who attended the 2010 Olympics in Vancouver.

A number of top world leaders are skipping the Olympics, however, including:

- Canadian Prime Minister Stephen Harper.

- U.S. President Barack Obama.

- French President Francois Hollande.

- British Prime Minister David Cameron.

- German President Joachim Gauck.

The Games come amid Western criticism of Russia's record on human rights and its law banning gay "propaganda" among minors.