District officials said the activists of both political parties clashed at Kachua under Raha assembly constituency of Central Assam.
AIUDF President and Lok Sabha MP Maulana Badruddin Ajmal addressed a rally at Kachua this morning, which was part of the party's mass programme in the run-up to the panchayat polls in Assam.
After Ajmal left the venue, a bike rally taken out by supporters of Congress reached the spot.
Soon after a scuffle broke out between the Congress and AIUDF workers, which left six persons injured, officials said.