About 30 people armed with sticks and sharp weapons attacked Hahim Constituency contestant Dhiren Chandra Rabha after he got out of his vehicle to visit the venue at Maumim under Boko Police Station.
Rabha was hospitalised in a serious condition, sources said, adding, that investigations into the matter have been initiated and security measures stepped up in the area.
The district has been witnessing violent incidents since the announcement of the Council hustings, to be held between November 13 and 25, last month.