Kizza Besigye casts his vote Uganda
Opposition leader Kizza Besigye has been 'driven back home' by police, a police spokesman told the BBCReuters/James Akena

Uganda's capital remains tense after police arrested Dr Kizza Besigye, incumbent President Yoweri Museveni's main challenger in the country's election, during a raid on the opposition party's headquarters on Friday (19 February).

Fears of violence have been running high since 15 million Ugandans voted in presidential and parliamentary elections on 18 February, in which Museveni, who has ruled Uganda for 30 years, is seeking a fifth term in office. Museveni, who is the National Resistance Movement's (NRW) flag bearer, told voters at his polling station in Kaaro in Rushwere that his NRM party "will obviously win".

Facing Museveni in the general election are Besigye – and Amama Mbabazi, a former prime minister and founder of Museveni's National Resistance Movement (NRM) party, who is running under the GoForward banner after failing to win the NRM nomination.

Besigye arrested, party HQ sealed off

Besigye was arrested alongside Forum for Democratic Change (FDC) leaders, including Mugisha Muntu, FDC party president and party chairman Wasswa Biriggwa as well as Ingrid Turinawe, a party activist. The men, who police said 'had been picked up during a meeting' have been taken to an unknown location.

This is the second time in two days that police have arrested Besigye, after he was detained on election day following claims he had exposed a house in Naguru, Kampala, as a vote-rigging centre, according to Kampala-based Al Jazeera correspondent Malcolm Webb. Besigye was "driven home'" to Kasangati in the evening, his party confirmed. (Full story here).

However, earlier on Friday riot police sealed off FDC's tally centre - located within the party's Najjanankumbi headquarters, after requesting that the party cancel a planned press conference. Party officials confirmed men inside the compound refused, prompting riot police to throw teargas canisters at the party supporters who had congregated at the gates to the headquarters.

Police then sealed off Entebbe Road where the FDC's head office is located, after witnesses saw riot police engaging FDC supporters in running battles on the road.

An FDC official said: "Only a handful of FDC top officials have been removed from (the) HQ. The fate of other staff remains unknown".

Besigye accused of leaking 'poll results' early

Senior police officer Felix Andrew Kaweesi told local media the men had been arrested because they had announced early poll results.

"We are not stopping FDC from tallying their votes but they shouldn't announce anything, its only (the Electoral Commission) to do so" Kaweesi told reporters. "We cannot take any chances as far as FDC is concerned."

Meanwhile, reports have emerged of both police and army sealing off second main opposition leader Amama Mbabazi's house in Kololo.

UPDATE:

13:17 GMT There areprotests and people are see burning road blocks near Katwe and the FDC party office, according to Al Jazeera correspondent in Kampala, Malcolm Webb. Police and military have fired teargas. Webb said he had seen "one man with gunshot wound".

A video has emerged of police arresting teenagers and asking them to climb in a police struck.

13:33 GMT Contrary to police claims that Besigye had been driven home, Winnie Byanyima, executive director of Oxfam International, has said that the opposition and his colleagues are held at Nagalama police station, outside Kampala.

Video of the arrest of the three top FDC officials in Kampala on Friday 19 February