The Congress workers were protesting against the Punjab Revenue Minister Bikram Singh Majithia, whose name has been cropped up in a multi-crore international drug racket.
Three separate factions of Congress activists wanted to stage a protest against the Akali government near Bath Castle, about 12 km from here.
The activists were sporting black flags and raising slogans against Chief Minister Parkash Singh Badal and Majithia.
However, they were intercepted by the police, which prevented them from reaching the venue.
Bhola recently accused the Revenue Minister of being "directly involved" in the drug trade in the state, a charge vehemently denied by the minister.