Police detained four 'hijackers from Dhaka with handmade bombs on Tuesday.
The law enforcing agency also suspects the detainees' involvement in Sunday's incident of snatching Tk 20 lakhs from a businessman after shooting him at Dhaka's Goran area.
Mostafizur Rahman, Officer-in-Charge of Khilgaon Police Station, told reporters that three hijackers, identified as Ali (25), Hossain (27) and Hridoy (28), were arrested from a dumped building at Goran.
On the basis of the trio's information, one Riyad (26) was arrested, the OC added.
He said the detainees are members of a hijacking gang. Two handmade bombs and bomb-making equipment were recovered from their possession.
"Members of this very gang were involved in Sunday's hijacking," Mostafizur Rahman said.
Police is interrogating them for further information on Sunday's mugging incidents. On Sunday, muggers allegedly snatched Tk 1, 09, 80,000 in cash leaving three people injured in three separate incidents in the capital.
In one incident, criminals shot a group of bKash agents in the capital city's Rupnagar of Mirpur and took away Tk 90 lakh.
The second incident took place at the same area, where muggers snatched Tk 80,000 from Abdul Aziz (30), who was returning to his residence from Sayedabad Bus Stand by a CNG-run auto-rickshaw.
And the third incident took place at Goran where muggers shot a businessman and snatched about Tk 20 lakh from him.