Heavily armed police have surrounded the headquarters of Uganda's main opposition party and fired tear gas from a helicopter to disperse a crowd, raising tensions amid mounting allegations of vote rigging in elections.
Kizza Besigye, the main rival to President Yoweri Museveni, was holding a meeting with other leaders of his party when police tried to force themselves into the premises, said Ingrid Turinawe, an aide to Besigye.
"The police basically invaded us," she said. "They are creating a lot of confusion because they don't want Ugandans to know the truth. We are not going to accept this."
Besigye's supporters resisted the police, who took up positions outside the headquarters of the Forum for Democratic Change party.
Besigye's party is running its own tally centre and has discovered that some or the results being announced by the election commission are a "concoction", Turinawe said, noting the election commission is announcing results according to tallies from polling stations, not according to districts as had been expected.
Provisional results released on Friday showed Uganda's long-time president with an early lead over his main rival in the country's presidential elections.
Museveni has 62 per cent of the vote and Besigye has 33 per cent, according to results from about 23 per cent of polling stations across the country as announced by the election commission. Final results are expected Saturday.
The voting Thursday suffered delays in delivery of voting materials, especially in areas seen as opposition strongholds.
Voting is taking place Friday at 36 polling stations in Kampala and the neighbouring district of Wakiso where no voting took place on Thursday. More than 15 million people were registered to vote, with members of parliament also up for election.
Besigye was briefly arrested late on Thursday after visiting a house in Kampala where he suspected ballot-stuffing was taking place. Police said the house was a security facility and accused Besigye of trespassing on government property.
Museveni, 71, took power in 1986 and pulled Uganda out of years of chaos. He is a key US ally on security matters, especially in Somalia. His critics worry he might want to rule for life, and accuse him of using security forces to intimidate and harass the opposition.
Besigye, 59, was Museveni's personal physician during a bush war and served as deputy interior minister in Museveni's first Cabinet. He broke with the president in 1999, saying Museveni was no longer a democrat.