BJP president Amit Shah Tuesday launched a scathing attack on the Trinamool Congress government in West Bengal, and charged Chief Minister Mamata Banerjee of jeopardising national security for the sake of vote bank.br br Addressing a Bharatiya Janata Party rally in Burdwan where an explosion killed two Bangladeshi militants, Shah said the blast took place only because the Trinamool was sheltering Bangladeshi infiltrators.