Security forces on Monday evening fired live bullets to disperse supporters of Opposition supporters who were marching in the town.
Some bullets reportedly hit and killed Yasin Kawuma, who was driving the car Kyaddondo East MP, Robert Kyagulanyi, aka Bobi Wine. Four people reportedly injured.
Arua Resident District Commissioner, Mr Peter Dibele could not confirm the death or the number of people who were injured.
"I only heard gunshots and my officers are still gathering information. I am also getting it on the media and I can't confirm about the deaths," he said.
Mr Kyagulanyi posted on his twitter account, a picture of the seemingly lifeless Kawuma.
Trouble started after different candidates were marching to their respective offices with supporters after campaign rallies ahead of Wednesday by-election to choose Arua Municipality Member of Parliament.
On Dorcus Inzikuru Street, supporters of Mr Kassiano Wadri Kassiano, an Opposition leaning candidate, were marching ahead of supporters of Ms Nusura Tiperu, the National Resistance Movement (NRM) candidate.
Suddenly, gun shots were fired on Mr Wadri's group, forcing them to scatter.
The group retaliated by hurling stones at security forces.
Mr Kyagulanyi is one of the politicians who were in the town to campaign for Mr Wadri. President Yoweri Museveni also campaigned for Ms Tiperu.