At least six cocktails were exploded near the BNP’s central office at Nayapaltan of the capital around 1:30pm on Monday.
A procession of Jatiyatabadi Chhatra Dal (JCD) activists was heading to Bijoy Nagar from the BNP central office at that time.
Selina Parvin, sub-inspector of Paltan police station, said, "We are yet to identity the culprits behind the cocktail blasts. Police are searching the adjacent areas to find them.
"Additional police personnel have been deployed around the BNP office," she added.
Earlier in the morning, JCD leaders and activists demonstrated in front of the BNP office, protesting against the expulsion of their leaders from the student front.