Ugandan police fired tear gas for a second consecutive day on Thursday to disperse supporters of presidential contender Amama Mbabazi, who is seeking to unseat veteran leader Yoweri Museveni in next year's elections.
Former prime minister Mbabazi, 66, has emerged as a strong challenger to his one-time ally Museveni, who has ruled the east African nation since 1986.
Mbabazi, an influential figure in the ruling National Resistance Movement (NRM) before he quit the party, has held large rallies across eastern Uganda since Monday.
Mbabazi's spokeswoman, Josephine Mayanja-Nkangi, said one of Mbabazi's bodyguards was wounded in the leg when police fired tear gas and live bullets to disperse his supporters in Jinja, an industrial town 90 km (56 miles) east of the capital Kampala.
"A large crowd had gathered... but police were determined to stop Mbabazi from addressing them, so they again fired tear gas and live bullets," she said, adding that a police truck had rammed Mbabazi's vehicle.
Polly Namaye, the police spokeswoman, denied security forces had used live bullets.
"Mbabazi has been told to stick to consultative meetings in enclosed venues but he wants to do rallies. Police have a mandate to stop any violations of electoral laws," Namaye said, adding that she had not received reports of injuries.
Government officials say Mbabazi's mass rallies are illegal as he has not yet been formally nominated by the electoral commission for the polls to be held in February and March next year.
On Wednesday, police also fired tear gas in Soroti, a town in northeast Uganda, to scatter a rally of Mbabazi's supporters shortly before he was to address them.
Museveni's critics have accused him of using strongarm tactics to retain power and quell growing frustrations over corruption and perceptions the 71-year-old wants to remain president for life.
Mbabazi is running as an independent candidate after his bid for the NRM ticket was frustrated.
Charles Rwomushana, Kampala-based political analyst and former intelligence operative, told Reuters the government had been blindsided by the size of Mbabazi's rallies.
"They thwarted his bid for the NRM ticket and thought that would kill his momentum," he said. "You will see more tear gas."