The victims, including two children, were standing on a temple palanquin when it came into contact with an electric line at Appar temple in Kalimedu, Indian broadcaster NDTV reports.
The temple palanquin came into contact with the overhead line while taking a turn, according to officials.
The injured have been admitted to a local hospital for treatment.
"A case has been registered in the matter and an investigation is underway," said V Balakrishnan, Inspector General of Police, Central Zone, Tiruchirappalli.
A video of the incident shows the chariot being completely destroyed after coming into contact with the electric line.
The annual chariot festival is observed by a large number of devotees in Tamil Nadu every year.
