The Ugandan opposition leader, Kizza Besigye, has been charged and remanded in custody after being arrested at a protest march for the fourth time in two weeks. Besigye was detained for leading a crowd towards the centre of Kampala in the fourth of a series of "walks to work" protests against high food and fuel prices in the country. He was remanded in custody until 27 April after being charged with participating in an unlawful assembly, a witness said. Besigye's car was surrounded by hundreds of chanting supporters when riot police moved in. Police fired teargas and rubber bullets to disperse the crowd. He was bundled into a van and taken to a police station before being transferred to another police post beside a heavily guarded courthouse on the outskirts of the capital, a witness said. Police spokesman Vincent Sekate said: "All I can say is that we have him. He attracted a crowd and when it started being rowdy, we came in and decided to arrest him and create order again."