Nine more athletes, including six medal winners, were retroactively disqualified from the 2008 Beijing Olympics on Wednesday after failing retests of their doping samples.

The International Olympic Committee announced the decisions in the latest sanctions imposed on athletes whose stored samples came back positive after being retested with improved methods.

Four athletes were stripped of silver medals and two of bronze medals in weightlifting, wrestling and women's steeplechase. All six athletes come from former Soviet countries — Russia, Belarus, Ukraine, Uzbekistan and Kazakhstan — and all tested positive for steroids.

The IOC stores doping samples for 10 years to allow them to be reanalyzed when enhanced techniques become available. The IOC recorded a total of 98 positive cases in recent resting of samples from Beijing and the 2012 London Olympics.

Stripped of silver medals Wednesday were freestyle wrestlers Soslan Tigiev of Uzbekistan (66-74 kilogram division) and Taimuraz Tigiyev of Kazakhstan (84-96 kg) and weightlifters Olha Korobka of Ukraine (75 kg) and Andrei Rybakov of Belarus (85 kg).

It's the second time Tigiev has been stripped of an Olympic medal for doping. He lost his bronze medal from the 74 kg event at the London Games after failing a drug test.

The IOC stripped Beijing bronze medals on Wednesday from Russian steeplechaser Ekaterina Volkova and Belarusian weightlifter Anastasia Novikova (53 kg).

The IOC asked the international weightlifting, wrestling and track and field federations to modify the Olympic results and consider any further sanctions against the athletes. Decisions on reallocating the medals have not been finalized.

The IOC said all six medalists tested positive for the steroid turinabol. Rybakov and Novikova also tested positive for stanozolol. Both substances are traditional steroids with a history dating back decades. The new IOC tests used a technique that could detect the use of those drugs going back weeks and months, rather than just days.

Also disqualified Wednesday were Cuba's Wilfredo Martinez, who finished fifth in the men's long jump; Nigerian-born Spaniard Josephine Onyia, who was eliminated in the semifinals of the women's 100-meter hurdles; and weightlifter Sardar Hasanov of Azerbaijan, who competed but did not finish in the men's 62-kg division.

The IOC said Hasanov tested positive for turinabol, Martinez for the diuretic and masking agent acetazolamide, and Onyia for the stimulant methylhexanamine.

Last week, the IOC announced that Russian weightlifter Apti Aukhadov had been stripped of his silver medal from the London Olympics on Tuesday after testing positive for turinabol and drostanolone.