Uzbekistan’s government has said it will conduct a fresh investigation into the territory of a former U.S. base over new claims it was a site of chemical and radiation contamination.  

The announcement made on February 17 by Islombek Bokijonov, deputy chairman of the State Ecology Commission, appears to have come in response to a January executive order from former U.S. President Donald Trump mandating an investigation into evidence that U.S. troops might have been exposed to toxic substances at the Karshi-Khanabad base, also known as K2.

The Soviet-built base was established in a location 145 kilometers north of Afghanistan’s border to enable the U.S.-led Operation Enduring Freedom, which was launched in the wake of the 9/11 atrocities. U.S. troops retained their presence there until 2005.  

Trump’s executive order was in turn triggered by a CBS News investigation that revealed how an abnormally large proportion of former service personnel that had passed through K2 are now suffering from rare cancers and other illnesses.

Bokijonov offered some early theories in his announcement. Cotton fields were routinely sprayed with chemicals and herbicides in Soviet times. Although 33 Soviet-era chemicals storage sites have been shut down, another 17 still remain, Bokijonov said. One might have been located on the grounds of the K2 base, he said.

Uzbek military sources are dismissing such talk as speculation, however.

Defense Ministry spokesperson Bahrom Zulfikorov said on February 18 that suggestions that K2 base was contaminated with radiation or chemicals were merely the ill-founded opinions of non-specialists.

“The U.S. contingent was there for less than five years. We have soldiers that served there for 15-20 years, some for their entire lives. Officers rotate every five years, but plumbers, guards, technicians can be there for up to 30 years. And they do not have things happening to them like U.S. military personnel do,” Zulfikorov said. 

Nosir Fozilov, head of the military medicine department at the Tashkent Medical Academy, said that communities near K2 base also underwent medical checks and that tests showed no anomalies.

Zulfikorov said any further comments about K2 would be issued only at the “highest government level, through diplomatic channels, so as not to harm relations with the United States.”

The agreement between the U.S. government and Uzbekistan allowed for use of Uzbek airbase and the stationing of 1,500 troops there.

But the fate of K2 was thrown into doubt as early as 2004, when Washington slashed aid to Tashkent over concerns at the human rights record of the late President Islam Karimov’s government.

Matters came to a head after May 2005, when Karimov ordered the bloody suppression of a major uprising in the Ferghana Valley city of Andijan. Irked by the U.S. State Department’s calls for an independent investigation into the massacre, Karimov’s government eventually ordered that the U.S. leave K2 by the year’s end. The last U.S. forces pulled out of K2 in November 2005.