Forty top leaders of Islamist militant outfits are regrouping with their 10,000-plus cadres in south-western Bangladesh in districts bordering India's West Bengal state, authorities have said.
Bangladeshi authorities say they gleaned this information after interrogating Hizb-ut-Towhid militants who were arrested in this border town last week.
Hizb-ut-Towhid is an Islamist terror group run by Bayezid Khan Panni. The outfit is banned in several countries.
Prime Minister Sheikh Hasina has now asked the home ministry to update its dossiers on militant bodies.
The ministry found that of the 33 groups identified so far, four were banned by the Khaleda Zia government after protests at home and an international outcry against activities of the Islamist militants.
The Daily Star quoted unnamed sources in the intelligence agencies as saying that the law enforcers were trying to hunt down the chiefs of those outfits holed up in various districts.
The Hasina government has set up a 17-member task force headed by State Minister for Home Tanjim Soheh Taj to tackle the spread of militancy.
The outfits operating in the region are Allahr Dal, Jama'atul Mujahideen Bangladesh (JMB), Harkat-ul Jihad al Islami (Huji) and Hizb-ut Towhid.
Panni is currently leading Hizb-ut Towhid. He has written several books to indoctrinate his followers and also distributes leaflets.
According to police, during interrogation Hizb-ut Towhid men told them Panni invited them to prepare for "direct combat".
Police said a large number of members and leaders of the organisation are well-trained and motivated.