The mishap occured near Gonava crossing last night when truck driver, identified as Bablu, crushed the members of a marriage party, who were dancing on the streets on way to the venue at Harnaut Agriculture farm, Additional Superintendent of Police (ASP) Vibash said.
Three members of the party died on the spot, while 12 others sustained injuries, he said.
The truck hit a jeep and a car before running over members of another marriage party nearby in which one more person was killed and several others injured, the ASP said.
The truck driver allegedly deliberately ran over the members of the marriage party at the wedding of Krishna Kant Prasad's niece to settle score with the latter with whom he has had a running dispute over landed property, Vibhash said, adding that a probe was on in the matter.
The incident sparked off strong protest by the local people who torched two trucks and damaged several shops in Harnaut market before blocking NH-31 demanding arrest of the culprit, the ASP said.