An Awami League politician was among four people detained by the elite Rapid Action Battalion (Rab) in connection with the Shahjahanpur shooting in which ruling party member Zahidul Islam Tipu and a college student were killed.

The detainees have been identified as Omar Faruk, 52, general secretary of No 10 ward unit of the Awami League, the alleged mastermind, and Abu Saleh Shikder (38), Nasir Uddin (38), and Morshedul Alam (51).

According to Rab, the killing was the fallout of a longstanding enmity between the two AL politicians over the control of a slew of illegal businesses and establishing supremacy in the Motijheel area.

Also read: Shahjahanpur double murder: Second suspect put on 1-day police remand

Acting on a tip-off, the elite force conducted raids in Mugda, Shahjahanpur and Mirpur areas of the capital and detained them on Friday night.

"Our men nabbed them from different parts of the city," said assistant director (media) at RAB headquarters ASP Imran Khan. "We have also seized a bike used in the crime, Tk 3.30 lakh in cash and some mobile phones from their possession."

During questioning, the Rab said, the detainees had admitted to their involvement in the murder of Tipu.

"There had been a longstanding enmity between the two AL politicians over the control of toll collection and school-college admission racket in the Motijheel area," said Commander Khandaker Al Moin, director of the legal and media wing of RAB.

During investigation, the elite force claimed to have identified a man named Musa, who's based in Dubai. "He probably ordered Tipu's killing. Musa's arrest will only help unravel the bigger plot and who had actually shot Tipu dead," said Moin.

“Efforts are on to take legal steps against the detainees,” said the Rab director.

On the night of March 24, Tipu, who was on a microbus, and Samia Afrin Priti, a 22-year-old college student, who was returning home on a cycle rickshaw, were killed in firing in front of Islami Bank Hospital.

Also read: Shahjahanpur double murder: Second suspect held with gun

Tipu was a former general secretary of the AL Motijheel committee while Priti was a student of Begum Badrunnesa Government College. Tipu’s driver was also injured in the firing.

They were all stuck in a traffic jam in the area when a biker wearing a helmet and a mask appeared from nowhere and fired at them, according to police.

The next day, a case was filed against unidentified people over the double murder.

On March 27, police arrested Akash, 34, identifying him as the prime accused in the double murder case from Bogura district. The next day, a Dhaka court placed Akash on a seven-day police remand for custodial interrogation.

And on March 31, a second suspect was arrested by Dhaka Metropolitan Police detectives from the city’s Kamalapur area.