Police sought seven days to grill BNP leaders Selima Rahman, Khandaker Mahbub Hossain and Fazlul Haque Milon in a blast case on Wednesday afternoon.
Investigation Officer of the case, Thakur Das Malo, submitted the remand plea to the court of Dhaka Metropolitan Magistrate Amirul Hoque.
The trio were shown arrested in a case of blasting crude bombs near the office of Dhaka Metropolitan Police in Ramna area of the capital on January 4.
BNP Vice Chairperson Selima Rahman was detained from her residence on Tuesday evening after she announced an extension to the party's hartal.
Earlier, BNP chairperson's advisor Khandaker Mahbub Hossain and the party's Organising Secretary Milon were detained on Tuesday afternoon.
Though running MP Nizamuddin Ahmed was also detained on Tuesday, he was later released in the night, detective police Joint Commissioner Monirul Islam said.