Kolkata, June 15 (ANI): BJP delegation on Sunday visited Kolkata in order to investigate the violence unleashed on BJP workers in West Bengal. BJP leader Balbir Punj said that violence against political workers has increased under Chief Minister Mamata Banerjee. Punj also stated that the BJP delegation has arrived only to investigate the violence against BJP leaders and workers. Several BJP workers were injured during the clash between BJP and TMC supports. The BJP leaders will also visit Illambazar where a BJP leader was killed.