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.
He has 62% of the vote, while Mr Beisgye has 33%, according to provisional results released by the electoral commission.
There is a heavy deployment of police and soldiers in neighbourhoods around the headquarters of Mr Besigye’s Forum for Democratic Change (FDC) party, reports the BBC’s Catherine Byaruhanga from Kampala.
A police helicopter has also been flying overhead.
The police have not yet commented on the reason for Mr Besigye’s arrest.
This is the third time in the space of a week that he has been detained.
Voting is still taking place in a handful of places where the late arrival of election materials meant that polling stations did not open on Thursday.
Social media was also blocked on Thursday in Uganda to prevent people from spreading “lies”, Mr Museveni said.
Critics said the decision showed that Mr Museveni, one of Africa’s longest-serving rulers, was becoming increasingly tolerant.