Ugandan police on Monday arrested opposition leader Kizza Besigye as he tried to stage a protest in Kampala, police spokeswoman Judith Nabakooba told AFP.
"He was arrested after blocking a road leading into Kampala," she said. "Police tried to move him on but he resisted."
"Teargas was used to disperse a rowdy crowd that was throwing stones," the spokeswoman added.
Besigye, who was President Yoweri Museveni's main challenger in February 18 presidential elections he claims were rigged, had called for a "walk-to-work" demonstration against rising fuel prices.
The east African country's police has banned demonstrations and warned last week that any attempt to stage street protests would be "dealt with firmly".
"I would like to caution any persons organising these illegal activities that as custodians of the public interest, the police shall not allow them to take place," police chief Kale Kayihura said in a statement Friday.
Besigye had warned before the February polls that Uganda was ripe for an Egypt-style revolt but stopped short of calling for mass street protests to challenge the results, which saw Museveni re-elected with a landslide.
"We are not going to be intimidated. People have a cause to hold a peaceful demonstration. We are not going to be deterred," Besigye told AFP on Friday.