The gang, Idul Group, looted Tk 1.17 lakh from the shop, before police shot and arrested Idul, the ringleader.

Idul is allegedly backed by a leader of BNP's student wing Jatiyatabadi Chhatra Dal (JCD), Dhaka University unit.

Slain Assistant Sub-Inspector (ASI )Aminul Islam and Havilder Liakot Ali were members of a special police team engaged in the recently-launched anti-crime drive in the city styled 'Operation Cobra'.

"It was around 3:30pm when four armed youths came to my office," said Albert Gomes, managing director of AJ Money Changers Limited at BCIC Sadan at Motijheel.

"One of them stood guard at the entrance and the leader of the group held a pistol against my head and asked me to hand him cash," Albert told The Daily Star.

"I obeyed them and gave them Tk 57,000 from the vault. They also took Tk 3,000 from my purse," he said.

The robbers took three mobile phones from Albert's locker and one from his staff. At that moment, two unsuspecting customers stepped in and the robbers also stripped them of their cash.

"They pointed a firearm at me and grabbed Tk 55,000 I had with me to buy dollars," said one of the customers, Emdadul Haq Babul.

The gang also took Tk 1,900 from Masum Parvez, a staff of the adjacent Shapla Products office.

"While leaving, one of them shouted at me, 'you will be killed if you go out in half an hour'," Albert said, adding that he heard gunshots minutes after the extortionists left his room.

Tipped off about a possible operation by the Idul Group, a six-member police team led by Inspector Salahuddin rushed to the area in a white microbus. The policemen took position near the building.

As the robbers emerged from the building, the law enforcers caught two of them -- Idul and Kiron.

"When the robbers were being dragged towards the microbus, Idul suddenly pulled out a pistol and shot ASI Aminul Islam in the abdomen pointblank," constable Nizam, who was posted near the building gate, told The Daily Star.

As the policemen were caught by surprise, Kiron also struggled himself free and both Idul and Kiron dived to the ground, firing.

"Other members of the gang, who were scattered around, also started firing. I took shelter under a rickshaw-van and kept on pulling the trigger till my gun magazine was empty," said the constable, who received pellet injuries.

The extortionists exploded several bombs this time to make their escape, leaving wounded Idul lying on the street.

As the eight-minute mayhem ended, ASI Aminul and constable Liakot were found lying on the street. Aminul also received bullets in his chest, Liakot in the ribcage and a police informant, Quddus, in his right knee.

Police arrested Idul with bullet wounds in the chest and found Tk 20,000 on him. Police recovered a sophisticated CZ pistol, two magazines and 30 rounds of bullets.

Other members of the team -- Inspector Salahuddin, Sub-Inspector Aziz and Sergeant Zahid -- took the victims to Dhaka Medical College Hospital (DMCH). Idul was admitted to ward No. 30.

During a visit to the DMCH, this correspondent found police guarding Idul in the ward.

Police received the bodies of Aminul and Liakot at 7:15pm on completion of post-mortem and took them to Rajarbagh Police Lines. They will be buried tomorrow.

Identifying Idul as a top criminal of Motijheel, Sutrapur, Demra and Sabujbagh, police said he has at least 15 murder cases against him.

Some sources identified him as a close aide of a BNP leader with the status of a minister.

Following a clash with his rivals at Gopibagh one and a half years ago, Idul and his associate Millat used to stay at room No. 209 and 210 at Jahurul Haque Hall of Dhaka University under the shelter of Tanjilur Rahman Tanjil, JCD's hall unit president, sources said.

The criminals were allegedly involved in snatching on the university campus. They snatched the passport and foreign currencies from a pedestrian in front of the British Council a couple of months ago.

They collected toll from a shop in front of the Shishu Academy fourth class employees' union office. The gang also controls drug business inside the hall and collects toll from university hall canteens and shops.