BERLIN -- Two athletes tested positive for the steroid THG out of 402 samples analyzed from track and field's world championships, the sport's governing body said Saturday.

The identities and nationalities of the athletes were not disclosed by the International Association of Athletics Federations.

However, one of the two is one of the five who previously tested positive for the new designer drug, a track official told the AP Friday on condition of anonymity.

Any athletes found guilty of using THG would face two-year bans and be stripped of their results, including medals, from the championships.

Five have already known to have tested positive for THG -- four Americans and British sprinter Dwain Chambers.

IAAF general secretary Istvan Gyulai said the two athletes were from different countries and "there were no surprises for IAAF."

Chambers, the European 100-meter champion, tested positive in an out-of-competition control in Germany in August and has been suspended pending a hearing by UK Athletics.

The names of the four U.S. athletes who tested positive at the national championships in June at Stanford, Calif., have not been officially announced. But several news organizations, including the AP, have identified three of them as middle-distance runner Regina Jacobs, shot putter Kevin Toth and hammer thrower John McEwen.

THG, or tetryahydrogestrinone, was uncovered last summer as a steroid modified to avoid detection in standard drug tests. After a test was devised by the UCLA doping control lab, the IAAF decided to recheck the stored samples from the championships.

The U.S. Anti-Doping Agency has identified California's Bay Area Laboratory Co-Operative as the source of THG, an accusation denied by BALCO owner Victor Conte. IAAF president Lamine Diack said the results of retesting "make it very clear" track athletes using THG were "concentrated around BALCO."

In other developments at the IAAF meeting: