They tried to blow up the flat at the six-storey building “Rubi Villa” keeping a grenade on a stove after filling their room with gas when the raid was underway, Rab Director General Benazir Ahmed said at a press briefing.
But by the grace of the Almighty, they failed," he said.
He added that three bodies were found inside the room after the raid at the suspected militant den in West Nakhalpara area.
The three are possibly aged between 20 and 30. They rented the room on January 4 last year showing a fake National Identity card (NID), he further said.
The land lord had no idea about them as a man named Rubel was in-charge of renting the flat as a mess, the Rab official added.
Bomb disposal units of the law enforcers are working to deactivate the explosives kept at the den, our staff correspondent said.
Earlier in the day, sounds of heavy gunshots and explosions were heard from the spot while Rab members conducted the operation on the fourth floor of the Rubi Villa, reports staff correspondent.
Parvej Hossain, a resident of the fifth-floor and a student of Tejgaon Polytechnic Institute, told The Daily Star they woke up hearing the heavy sounds of gunfire around 3:30am.
The residents of the fourth-floor were hardly seen and the door and windows of the floor remained closed at all times, Parvej said.
Residents of the house were brought out of the building safely before conducting the operation, Rab members said.
The law enforcers cordoned off the building around 2:00am suspecting that militants may hole up there, Mufti Mahmud Khan, Rab's legal and media wing director, told The Daily Star in the morning.
Sensing presence of the Rab members, the “militants” fired bullets and hurled grenades at the law enforcers, he said.
Later, the members of the elite force entered the “hideout” after breaking its door and conducted operation there, the Rab official said.
Two Rab members sustained minor injuries, he added.