Two more Russian athletes were stripped of their Olympic medals from the 2014 Sochi Games on Wednesday, leaving the United States as the country with the most medals.

Four Russians, all skeleton racers, were banned by the International Olympic Committee for doping, including men's gold medallist Alexander Tretyakov and women's bronze medallist Elena Nikitina.

Russia, which finished the games at the top of the medals table with 13 gold and 33 overall, has now been stripped of six medals based on evidence of a state-sponsored doping program in Sochi, including samples being swapped in the laboratory. Two of the six medals were gold.

The Russians still lead the medals table with 11 gold, tied with Norway, but have fallen behind the U.S in overall medals. The Americans, who won nine gold medals, have 28 overall, one more than Russia's current total of 27. Norway has 26 overall medals.

If the IOC decides to upgrade athletes who finished behind the banned Russians, the table would change again.

Two other Russian women who didn't win medals, Maria Orlova and Olga Potylitsina, were also banned Wednesday.

Russian federation proclaims innocence

Russian officials said all four banned athletes will file appeals.

"We are absolutely sure of the innocence of our athletes and will stand up for their rights," the Russian Bobsled Federation, which governs skeleton, said in a statement.

The previous six bans were in cross-country skiing. The cases against the Russians rest on evidence gathered by World Anti-Doping Agency investigator Richard McLaren, including testimony from the former director of Russia's anti-doping laboratories in Moscow and Sochi.

Without positive doping tests, the IOC disciplinary panel used evidence of coverups and tampering of sample bottles first gathered last year by McLaren's team.

The IOC will decide on Dec. 5 if Russia can compete at the 2018 Pyeongchang Games.

The ban for Tretyakov puts Latvia in line for its first Winter Olympic gold medal. If the IOC formally reallocates the medals, Martins Dukurs would be upgraded to gold. It would also mean silver for Matthew Antoine of the U.S. and bronze for Dukurs' brother, Tomass.

In the women's event, Nikitina's bronze would go to American slider Katie Uhlaender, who originally missed the podium by 0.04 seconds.

More sanctions expected

The IOC sanctions disqualify the four Russian skeleton racers from the Sochi Olympics and also ban them from all future Olympics.

Russian Olympic Committee president Alexander Zhukov said more sanctions are possible.

"I think we can expect the same decisions for the bobsledders and the female hockey players," Zhukov said. "The rulings are all the same."

Russia won two gold medals in men's bobsled at the 2014 Olympics, but there has been no official confirmation that the IOC is investigating. The Russian women's hockey team didn't win a medal.

The Russian government has repeatedly denied any involvement in doping or any coverups and says its athletes are being unfairly targeted. President Vladimir Putin has said the Olympic doping cases are part of an American bid to discredit his government ahead of presidential elections in March.