At least four BNP men have been injured, and seven vehicles were vandalized during a clash with police in Bogra on Sunday, the first day of the 48-hour blockade.
The incident took place at around 8am, when some BNP men blocked the Dhaka-Rangpur highway, and vandalized seven vehicles.
When police arrived at the scene, the BNP men detonated four to five cocktails at them.
The law enforcers later fired teargas shells to disperse the attackers.
Four people, including BNP's ward-13 local leader Mahbub Alam, were injured in police firing. Police, however, said they did not shoot anyone.
Bogra unit BNP Organising Secretary KM Khairul Bashar said their leaders and activists were holding a peaceful blockade in the Telipukur area around 8am on Sunday. At that time, the police came and opened fire with rifles.
Additional Superintendent of Police (Administration) Sigdh Akhtar said they did not fire any bullets. Protesters threw bricks and exploded cocktails at police.