Detectives have arrested four people over a crude bomb blast in front of Jatrabari police station that left a passerby seriously injured on Friday.
The arrestees are Md Rayhan Uddin, 35, Russell Khan, 32, Ala Uddin, 28, and Abdullah, 28.
Four crude bombs were also recovered from Lalbagh area based on information provided by one of the arrestees, said DMP's additional deputy commissioner (Media and Public Relations Division) Niaz Mehedi.
Following the blast on Friday, DB Wari division analysed CCTV footage and identified those involved, he said.
A DB team arrested Rayhan in Bangshal area on Saturday.
Based on information obtained from him, DB later recovered the four crude bombs wrapped in red adhesive tape from a sack of brick chips beside a pillar in the parking area of a 10-storey building on Zen Saha Road in Lalbagh on Sunday.
Three others were later arrested from Dogair area under Demra Police Station.
The arrestees were initially found to be active members of a banned political organisation, he said.
A case was filed against them under the Explosive Substantive Act with Jatrabari Police Station.
Operations are underway to arrest others involved in the blast, said Niaz Mehedi.