Police have arrested Uganda’s main opposition presidential candidate, a day after tightly contested elections, a BBC reporter at the scene says.
Kizza Besigye was detained during a raid on his party’s headquarters in the capital, Kampala, as he was about to hold a press conference.
Tear gas was also fired outside the building, our reporter says.
With official results for nearly half of the polling stations announced, President Yoweri Museveni is leading.
He is running for a fifth term, after 30 years in power.
This is the third time in the space of a week that Mr Besigye has been detained.
The police have not said why he was arrested or where he is being held.
It also criticised a temporary shutdown of social media, chat apps and mobile money services.
President Museveni said the decision had been taken for security reasons, and to prevent people from “telling lies”.