In a letter sent to the editor of a local Bangla daily 'Sunshine', the criminals also termed the government step to arrest the outfit's members and leaders "unjust."

Sent by post from Chapainawabganj, the letter was signed by a self-styled commander of the outfit, Ehsanul Azim.

The Sunshine authorities immediately informed the local police and district administration about it.

"The government will learn a lesson within several days," the letter reads demanding unconditional release of their leaders and members. "Jadid al Qaeda is a very powerful organisation, none should take it lightly," it added.

The other installations the militant outfit threatened to bomb include the National Museum, Chittagong airport, Jamuna Multipurpose Bridge, TV stations, Radio centres, and offices and publication points of different national newspapers.