"Unless the Jamaat is ousted from the ruling coalition, it is not possible to track down the masterminds behind the bomb attacks," ISA Ameer Syed Mohammad Fazlul Karim said at a press conference at its office in the city.

He also called on the four-party alliance government to step down if it is unable to resolve the national crises, including the rise of militancy.

The government's offer of dialogue with the opposition parties and professional bodies has been questionable, he said, adding that such dialogue is being arranged for its political gains.

The ISA ameer also alleged that the BNP-Jamaat alliance has been harbouring the militants' leaders Bangla Bhai and Shaikh Abdur Rahman, and thus tainting the image of Islam both nationally and internationally.

He also suggested engaging army men to crush the militants.

Karim, popularly known as Pir Shaheb of Charmonai, announced a series of programmes to protest the widespread corruption, rampant crimes and repeated bomb attacks.

The programmes included demonstrations at all Upazilas on December 15 and at all district headquarters on December 22. Protests will also be staged in Dhaka on December 27, in Khulna on December 30, in Rajshahi on December 19, in Sylhet on January 20, in Barisal on February 1, and in Chittagong on February 10.

The ISA will also stage a one-hour sit-in across the country from 12 noon on December 29 to protest the bomb blasts.