The Rapid Action Battalion yesterday arrested the owner of the Jhenidah mess where Nibras Islam, one of the Gulshan attackers, lived and the imam of a nearby mosque in Sonalipara village.
Later, the two were handed over to the local police station.
The arrestees are mess owner former army sergeant Kawsar Ali and imam Md Rokonuzzaman, said Rab-6 commander Maj Munir Hossain.
He said they arrested the duo around 7:30pm on information that they had recently returned to their home.
Kawsar's wife Bilkis Nahar alleged that law enforcers in plainclothes had picked up her husband and their two sons Binchar Ali and Benjir Ali a few days after the Gulshan attack.
Binchar and Benjir are still traceless, she said.
Rokonuzzaman had also reportedly gone missing.
Jhenidah Sadar Police Station Officer-in-Charge Harendranath Sarkar said Kawsar and Rokonuzzaman were handed over to them by the Rab.
He, however, could not immediate say what were the charges against them.