Uganda's presidential candidate Patrick Amuriat has been arrested in the capital, Kampala, at the headquarters of his Forum for Democratic Change (FDC) party
Soldiers and police officers have been heavily deployed at the party's offices, the Daily Monitor newspaper reports.
Mr Amuriat is reported to have vowed to defy restrictions on the number of supporters accompanying him to the electoral commission where he is scheduled to submit his nomination papers at midday.
The newspaper has tweeted a video of his arrest: https://twitter.com/DailyMonitor/status/1323520370981376000