The decision was taken at an emergency meeting of senior leaders of the parties -- the AL, components of the left-leaning 11-party alliance, Jatiya Samajtantrik Dal (JSD) and National Awami Party (NAP)-- held at AL's Dhanmondi office.

"Fundamentalist forces with direct patronisation of the BNP-Jamaat-led ruling coalition committed the crimes to destroy the country's democratic process and movement by the secular forces," AL General Secretary Abdul Jalil told reporters reading out a joint statement of the meeting.

The statement demanded immediate resignation of the 'Khaleda-Nizami' alliance government, admitting its involvement in the heinous crime and failure to ensure security of people.

"How can a bomb be blasted inside the airport through which Prime Minister Khaleda Zia left for China only two hours ago?" Jalil posed the question.

Such a devastating attack was not possible without the government's patronisation and involvement, he said.

The opposition leader also raised questions about State Minister for Home Lutfozzaman Babar's statement saying 'government had information about such attacks by some group between August 14 and 16'. "If so, why the government did not take any action to thwart the group's move and to nab the criminals," Jalil said.

He also alleged that through the bomb blasts, the government wanted to foil the opposition's united movement for reforms in the caretaker government system and election commission.

"We have been asking the government to take action against the militant groups. But instead of doing that, the government is protecting these groups," he alleged.

To protest the bomb blasts, the parties will hold two joint rallies in Dhaka -- one at the Central Shaheed Minar premises this afternoon and the other at Muktangon tomorrow. Similar demonstrations will also be held in other parts of the country.

AL leader Amir Hossain Amu chaired yesterday's meeting, attended by Tofail Ahmed, Abdur Razzak, Suranjit Sengupta, Rashed Khan Menon, Hasanul Haq Inu, Fazle Hossain Badsha, Pankaj Bhattacharya and Nurul Islam, among others.

Earlier, an emergency meeting of the AL Central Working Committee held at the party's Dhanmondi office also accused the government and militant groups of involvement in the bomb blasts.