Several people were injured when supporters of Mamat Orozbayev and Sanzharbek Kadyraliyev began throwing rocks and petrol bombs at each other in the town of Uzgen on Sunday. Gunshots were also heard, police said.
The local authorities had to close the polling station and suspend the vote.
The violence came after Kyrgyzstan's Supreme Court upheld June 14 an appeal lodged by Kadyraliyev against the election victory of Orozbayev, an ethnic Uzbek, and ordered a re-run in the district.
Uzgen is located between Osh and Jalalabad, major cities in southern Kyrgyzstan and centers of March 2005 popular uprisings known as the "tulip revolution," which toppled the republic's long-time leader Askar Akayev.
This April, the region was also a venue of mass protests against the slow pace of reforms promised by the new leaders.
