These NGOs fund militancy in the name of building mosques, setting up madrasas, other educational institutions, hospitals and healthcare centres. They also gave financial backing to the zealots involved in the recent countrywide bomb blasts, sources said.

The local administrations have been asked to closely watch and report to the higher authorities the activities of madrasas set up by the NGOs, particularly Qawmi madrasas that are not recognised by the government.

Some Islamic NGOs get foreign funds for non-conventional sectors like promoting Islamic culture by providing 'iftar' to people at mosques during the fasting month of Ramadan and sacrificing animals on the occasion of Eid-ul-Azha.

An Islamic NGO run by militant leader and Rajshahi University teacher of Arabic Dr Aasadullah Al Galib, who is now in jail custody, had provided over Tk 12 lakh for iftar at different mosque in Rajshahi during the last Ramadan, the sources pointed out.

The Islamic NGOs also get donations from individuals in the Middle Eastern (ME) countries for building mosques and looking after orphans. Intelligence agencies suspect a major portion of the money is used for arms training of Islamist zealots.

Islahul Muslimine, an Islamic NGO formed by Moulana Fariduddin Masud, arrested on charges of militant links, had transacted around Tk 1.50 crore last year. The government is looking into how and where the money was spent, sources mentioned.

Another NGO -- Al Markajul Islami -- run by a lawmaker get foreign donation for buying ambulances for carrying patients and dead bodies. Rabita Al Alam Al Islam, a Saudi Arabia-based international NGO, runs several hospitals in Cox's Bazar and the Chittagong Hill Tracts.

"Islamic NGOs get foreign funds for various projects. So, it is very difficult to trace the links between these NGOs and militants although the government monitors progress of the projects. Efforts are on to unearth the links," said a high official of the NGO bureau.

Director General of the NGO bureau Mostaq Uddin Ahmed however declined to say anything in this regard.

Officials of the Association of Muslim Welfare Agencies in Bangladesh (Amwab) denied involvement of Islamic NGOs with militants.

"We are working for welfare of the people, not for arms training. None of the registered Islamic NGOs has links to militancy," said one official.

But sources pointed out that the funds for militants comes through unofficial channels like hundi. It is very difficult to stop such flow of money without stopping hundi business in the country, they said.

Islamic NGOs mainly operate in the poverty-stricken northwestern districts like Rangpur, Dinajpur and Rajshahi. And Islamic militancy grew in those areas. The banned Jama'atul Mujahideen Bangladesh started work in Rajshahi and then in other areas.

Several hundred mosques were constructed or renovated in those areas in recent past by the Saudi Arabia-based Al Haramain Islamic Foundation. The government has it for alleged links to militants, and Kuwait-based Revival of Islamic Heritage Society.

Islamic NGOs are also active in the rural areas of Khulna and Satkhira districts, sources mentioned.