
Ariful Islam, Additional Superintendent of Police and Camp Commander of RAB-11 confirmed this at a press conference at the RAB-11 Narsingdi office.
They were arrested on Thursday afternoon during a joint operation by RAB-11 Narsingdi and RAB-12 Kushtia in Bottoil, Bhadalia area of Kushtia district.
The arrested couple, Rajon, 37, and his wife Zara, 30, are from Nawapara area under Madhabdi Police Station. During initial questioning, they admitted to being directly involved in the killing.
They are handed over to Madhabdi Police Station for further legal proceedings.
RAB said the operation to apprehend other suspects involved in the murder is ongoing.
Zahidul Islam, a union-level Chhatra Dal activist, was killed on December 29 after being lured from his home in Gayeshpur area of Zinaradi Union, Palash upazila, reports UNB.
His father, Mosharaf Hossain Bhuiya, filed the murder case naming Rajon, Zara, and four to five unidentified individuals as accused.