Police arrested three persons including a woman from Shibpur upazila of Narsingdi today in connection with the seven murders in Narayanganj.
The arrestees are Mintu, Masuma and Tipu.
Narayanganj Superintendent of Police Khandaker Mahid Uddin disclosed this at a press briefing in his office at noon. He however did not give details of the arrestees.
With this, a total of 15 people have been arrested in connection with the murders of seven people including Narayanganj panel mayor Nazrul Islam.
About the transfer of four police officials, the SP said that they have been shifted for the sake of transparent investigation into the sensational murder case.
The police officials are Akhter Hossain and Abdul Matin, officers-in-charge of Fatullah and Siddhirganj police station and Mahbubur Rahman and Abdul Awal, OCs of Detective Branch police.
Of them, Awal, who was probing the seven-murder case, was replaced by Mamunur Rashid Mondol in the wake of a controversy over his alleged links with the prime accused Nur Hossain in the murder case.
The new investigation officer of this case has already taken charge, the SP informed reporters.
"We will take all out measures including interrogations of people from any quarters, for fair investigation into the case," he said in response to a query.
Seven people including Nazrul and senior lawyer Chandan Sarker were abducted from the city on April 27. Six of their bodies were found floating in the Shitalakkhya river on April 29 while another body was found the following day.
Out Narayanganj correspondent reports, OC Awal was transferred to Barisal range.
Meanwhile, lawyers of Narayanganj Bar Association observed a one-hour token hunger strike at Narayanganj District Judge's Court premises demanding arrest of the killers.
Meanwhile, son-in-law of Chandan Sarkar, filed a murder case last night with Fatullah Police Station.