Police raided a residential area in Tongi near the Tamirul Millat Kamil Madrasa.
Gazipur Additional Superintendent of Police Russell Sheikh said the raid was conducted as part of a regular raid to stake out potential militant hideouts.
He said: “The raid is a follow-up to the recent anti-militant raids in Moulvibazar, Comilla and Sylhet.
Three people, including a madrasa student, were arrested on Thursday evening. Touhidul Islam, 17, a first-year Alim student, Abdullah, 30, and Anisur Rahman, 30, the latter two local traders, were arrested on suspicions of being involved with militant activities.
“We suspect militants might try to set up footholds in certain areas and are combing through them,” he added.
The area was also canvassed on Wednesday night by the police.