With the arrests of Mahbubur Rahman and Mahfuzar Rahman by the joint forces conducting a combing operation in the region to track down the militants, the number of arrestees rose to 23.

Police attached the property of Montejar Rahman, his son-in-law Mahfujar Rahman and uncle Delwar Hossain of Khetlal upazila. Montejar's house was being used as the venue of the gathering, which police raided early Friday following a firefight with the militants.

Police, however, did not release 12 villagers picked up Saturday for interrogation.

Interrogators say nearly 150 operatives of the outlawed group congregated at Montejar's house at Moheshpur village in Khetlal.

The operatives, trained up at different camps across the country over the last six months, gathered there for further instructions by top leaders of the organisation.

The interrogators, who grilled the arrestees and examined the evidence recovered from Montejar's house, said the outfit was formed in the late 1990s with financial support from extremists in Saudi Arabia.

The Jama'atul Mujahidin is the youth front of the Al Mujahidin, sources say.

"In Bangladesh, the party is led by Abdul Halim of Dhaka and its key objective is to establish the rule of the holy Quran and the Hadith through an Islamic revolution," Anwar Sadat, an arrestee and key accused of the Dinajpur bomb blast, told newsmen.

Police believe that Anwar, who is known as Obaidullah in Dinajpur, Abbas in Natore and Rajshahi, Amin in Panchagarh and Khalilur Rahman in Joypurhat, is the group's northern region boss.

"Most of the arrestees confessed that they gathered at the house for attending theoretical and combat training courses," agreed Abdul Jalil Mondol, superintendent of Joypurhat police.

"The arrestees are highly trained and remained tight-lipped about their leaders."

"We are ready to die in Jihad for establishing the rule of Allah," Rezaul, a sub-inspector of police, quoted one of the arrestees as saying.

Police say the outfit organises special training by holding a grand rally in every three months and has at least a 'well-organised' training centre in each division.

The training centres are located in mess-type rooming-houses closer to big towns and the cadres use mosques and madrassahs of the believers of 'Ahle Hadith'.

According to some reports, 38 militants were trained up between May 13 and May 18 this year at different training centres in Rajshahi, Natore, Bogra, Gaibandha, Joypurhat, Sirajganj and Dinajpur.

On January 9, about 12 militants were trained at Tiapara training centres of Sonatala upazila in Bogra and Uparbazar centre in Natore district.

Such training programmes were also held at Charmatha in Bogra, Ahmmedpur in Natore and in Chuadanga and Chandpur.

All these training were logistically supported by a man of Fulchhari in Gaibandha and another of a medical centre in Khilgaon in Dhaka, they said.

Meanwhile, most male villagers of Moheshpur fled their houses amid continued raids by the joint forces of police, Bangladesh Rifles and ansars.

Sabiha, a housewife, said her husband left the village to 'avoid harassment by police'.

Mahbubur Rahman, an arrested militant suspect, told reporters that he came to the village to see his grandfather, but police picked him up.