Is there political conspiracy behind Howrah violence?

The violence in Howrah has stirred politics of West Bengal. On the one hand, the BJP is taking jibe at Mamata Banerjee alleging that she failed to stop the violence, while on the other hand, Mamta Banerjee is accusing the BJP that it is responsible for this violence. However, the political dispute did not affect Howrah, where the violence continued for the second day. In Howrah, stone-pelters set the BJP office on fire, then the situation got worsen. Watch this video.