“Besigye has been arrested on the road as he walked with other people toward town. He is being held at Kasangati police station,” police spokeswoman Judith Nabakoba told Reuters.
A resident, Richard Kavuma, said Besigye was arrested just outside his home. The police forcibly loaded him on to a pick-up truck and drove him to the police station.
The protests began last week after prices rose because of a drop in food production caused by drought in the east African country and an increase in transport costs as a result of higher global oil prices.
The consumer price index jumped 4.1 percent in March from February, pushing the year-on-year inflation rate to 11.1 percent, the fifth rise in succession.
President Yoweri Museveni, who defeated Besigye in the presidential election in February, vowed to quash the protests on Saturday.