Officials in the Uzbek region of Karakalpakstan say thousands of people are being treated in hospital, after being injured during unrest on Friday.
Clashes broke out with the security forces when protesters took to the streets over plans to withdraw the territory's right to secede.
But at a meeting with local deputies on Sunday, he accused what he called malicious forces of trying to destabilise and undermine the situation in the Central Asian state.
Uzbekistan has a reputation for being one of the most repressive republics of the former Soviet Union, clamping down on any form of dissent.
Mr Ahunov, who is chairman of the opposition Berlik party, said he feared the potential for the situation to escalate into an ethnic conflict between Uzbeks and Karakalpaks, a minority group with their own language.
"There are still rallies going on in many locations," he told Reuters news agency, speaking from Sweden. "Overall, I think that the situation is starting to stabilise, but there is another kind of danger. There have been facts of ethnic clashes between the Karakalpaks and the Uzbeks.
"The situation can totally spin out of control. It will not be about the status of Karakalpakstan, it will be about a conflict between the Karakalpaks and the Uzbeks. It is the most dangerous thing."
According to AFP, videos that appear to show people dead and injured from the unrest have raised fears that the security crackdown took a high death toll.