The 72-hour countrywide blockade, called by the BNP-led 18-party opposition alliance, began on Saturday morning.
The blockade began at 6am Saturday and will end at 6am Tuesday.
On the other hand, Detective Branch (DB) Police held BNP Joint Secretary General Ruhul Kabir Rizvi and Executive member Belal Ahmed from their Nayapaltan office around 4:30am, hours before the blockade began.
On Friday, BNP Joint Secretary General Ruhul Kabir Rizvi announced the blockade at the party's Nayapaltan headquarters at 9:30pm.
Earlier they planned to observe demonstration programmes across the country on Saturday to protest the repression on leaders and activists.
