Riot police have deployed at Inzikuru Stadium in Arua District where more than 40 schools are converging for the district post-primary athletics competition.
The three-day field and track event which started on Friday have also attracted thousands of people scattered in the outskirts of the venue and in the nearby Barifa eucalyptus forests.
The annual event has become a cause of tension since acts of hooliganism dominate it.
Groups of students have reportedly formed gangs, purportedly to attack students from rival schools. Several stick-wielding groups have been seen moving around the stadium.
Police say they have deployed to avert any situation that could degenerate into violence.
Members of the force spent a better part of the morning in running battles with some of the students who had formed violent groups.
Police officers say most of the students engaged in the acts of hooliganism came to the stadium without school uniforms, while others are walking around bare-chested.
A teacher from Ombaci Secondary School said a number of students came with various types of alcoholic drinks which were hidden in the nearby forest and that the same groups are causing havoc at the venue.
There is a historical supremacy rivalry between Mvara SS, Arua Public SS, Arua SS Ombaci and Nile High School.
On Friday, the competitions were brought to a premature end after some students tried to invade the stadium. Police used teargas to disperse the crowd.
