Ugandan police on Thursday blocked opposition leader Kizza Besigye from driving from his home in Kasangati to Kampala city centre, saying the outing would spark criminal acts after he vowed to resume protests.
Besigye's car was stopped by police around his home outside Kampala and forced to return.
"They told me that I am under preventive arrest but I have never heard of that law," Besigye told AFP after returning home, adding that he was testing if the police would allow him free movement.
"I believe that we can seek an injunction to get these people away," he said, referring to the security presence around his home.
Police spokeswoman Judith Nabakooba however denied that the opposition chief was under house arrest, but said he had been stopped as he had vowed Wednesday to press on with his protests against the rising cost of living.
"He is not under house arrest," Nabakooba told AFP. "He is free. We only wanted to show him that we knew what he was planning to do and that it would lead to acts of criminality."
Besigye begun "walk to work" protests last month against soaring commodity prices, sparking a heavy police repression in which at least nine people were killed and the opposition chief injured.
He faces charges arising from the series of demonstrations that President Yoweru Museveni had vowed to end.