They have resumed organisational activities and are recruiting members, intelligence sources said. Their number could be over 1,000 across the country. Tangail being its birthplace it may have a good number of activists, they said.

They are under watch and law enforcers will son launch a drive to nab them and dismantle their dens, a source said.They had gone into hiding after the August 17 serial bomb blasts across the country last year.

The organisation headed by Bayezid Khan Panni of Karotia started its activities in Bangladesh in 1991.

Chittagong Metropolitan Police in raids in different areas of the port city on the night of August 10 arrested seven Hizbut Towhid men including an engineer of Chittagong Urea Fertiliser Limited (CUFL) and sales manager of a soft drink company.

Police also seized from them 200 leaflets and books, calling for establishing Islamic rule in the country through armed revolution.

During a primary interrogation the arrestees confessed to have been working for Hizbut Towhid in Chittagong for two years but denied having any link with outlawed Jama'atul Mujahideen Bangladesh (JMB).

Most of the armed activists of Hizbut Tawhid hailed from Basail upazila in Tangail district, a senior police official in Tangail said seeking anonymity while talking to this correspondent.

"Hizbut Towhid recently recruited armed activists from different parts of the district including Bathulee Sadi, Kashil, Kamutia, Basail and adjacent villages in the district", an intelligence official said.

They went into hiding after police arrested seven activists of the organisation from Chittagong recently, he added.

Maolana Abul Kalam Azad, an Imam of a mosque in Karotia, while talking to this correspondent said a good number of people including some educated persons from Karotia and adjacent areas joined Hizbut Towhid in last few months.

"A good number Hizbut Towhid men are active in all the 11 upazilas of the district. They are doing organisational activities secretly", he said.