"Detective Branch of [Bangladesh Police] picked up BNP Secretary General Mirza Fakhrul Islam Alamgir from his Gulshan residence in Dhaka around 9:25am [03:25 GMT] today," the BNP said on X, formerly known as Twitter.
The police cordoned off the residences of BNP standing committee members, Amir Khasru Mahmud Chowdhury and Mirza Abbas, in Shahjahanpur, Bangladeshi newspaper Dhaka Tribune reported.
The report did not specify the reasons for the detention.
The opposition party called for a nationwide strike on Sunday to protest against the police action in dispersing the anti-government protests in Dhaka's Kakrail district that took place on Saturday and reportedly resulted in the death of a police officer and injured over 200 people.