Several vehicles were set on fire, stones were thrown and shops ransacked as clashes between two groups broke out in West Bengal`s Howrah amid Ram Navami celebrations on Thursday. West Bengal Chief Minister Mamata Banerjee, who is on a two-day sit-in protest in Kolkata against Centre`s policies, called "rioters the enemy of the country" and said those behind the violence "will not be spared". While BJP leader Amit Malivya, denied her allegations and blamed the Trinamool government for the violence.