Clashes broke out between supporters of the BJP and the Trinamul Congress in Contai shortly after Amit Shah addressed a rally in the East Midnapore town on Tuesday, prompting the Union home minister to phone the chief minister.

At least 15 people were injured, over a hundred vehicles were damaged and a Trinamul office was ransacked in the vandalism and arson attack that lasted several hours.

Union home minister Rajnath Singh called up chief minister Mamata Banerjee and “expressed serious concern over reports of large scale violence and arson against people who participated in the political rally of BJP president Amit Shah”, the home ministry said in a statement.

Rajnath told the chief minister that those who indulged in violence should be brought to book, the statement added.

On her part, Mamata conveyed her concern to the home minister over “organised vandalism unleashed by BJP supporters”, said Derek O’Brien, Trinamul’s leader in the Rajya Sabha. “Are they political elements or hired goons from outside?” he wondered.