Ugandan police have briefly detained opposition leader Kizza Besigye and fired teargas to disperse hundreds of his supporters in the capital Kampala, officials say, just days ahead of Thursday's presidential election.
Besigye and six other candidates are seeking to end President Yoweri Museveni's 30-year grip on power. Analysts say that the veteran leader is expected to win the February 18 poll but that it represents his toughest political challenge yet.
Witnesses and supporters of Besigye said he was taken away from the rally by security forces. But police spokesman Patrick Onyango said Besigye was not arrested.
"What I can say is that Besigye is not under any arrest. Right now he's at his home," he told Reuters.
Besigye was detained after police asked him and his supporters to use a different route during their march into central Kampala, according to a witness at the rally.
"They wanted him to use another road which was far away from where he wanted to go. Police then started firing teargas and arrested (Besigye) with two other opposition leaders," said the witness.
A government spokesman said all campaigning has been prohibited in Kampala's central business district, where supporters of Besigye's Forum for Democratic Change (FDC) party were heading.
"It's unacceptable because it's congested already, so Besigye had to be stopped," Shaban Bantariza, deputy government spokesman, said.
The opposition leader has lost three previous presidential elections against Museveni and has been arrested many times, with police accusing him and his supporters of holding illegal rallies.
His supporters say such arrests are part of government intimidation tactics. They also accuse Museveni of rigging polls and using state funds to prop up his party, the National Resistance Movement (NRM). Officials deny all such claims.
Semujju Nganda, spokesman for the FDC, said Besigye has been barred from staging rallies in a Kampala stadium, and the party's options to campaign have been curtailed by the government.
"This has left us with no choice but to address voters on the streets and roads," Nganda told Uganda's Monitor newspaper after Besigye's arrest.
Museveni is credited with restoring economic and political stability after years of turmoil in the 1970s and 1980s. But critics say unemployment, especially among youths, has surged under his rule and accuse him of failing to tame rampant corruption.