The blast was reported at the location where members of Bangladesh Garment Manufactures & Exporters Association (BGMEA) were staging their protest.
No casualty was reported in the blast, bdnews24 reported.
Apex trade body Federation of Bangladesh Chambers of Commerce and Industries (FBCCI) on February 8 claimed Bangladesh suffered a loss of at least Tk 750 billion since January 5 due to disruptions caused by the blockade.
Business groups and chambers have been requesting the Bangladesh Nationalist Party to call off its agitation which has severely affected the shipment of goods.
Ex-premier Khaleda Zia's BNP has enforced a nationwide transport blockade since January 6 demanding a mid-term polls while Prime Minister Sheikh Hasina rejected the idea asking her arch rival to wait until 2019 when the next general elections are scheduled to be held.
Most of the victims of Opposition-led non-stop nationwide strikes are ordinary people who were killed in clandestine firebomb attacks on buses by suspected blockaders or hired goons. These attacks have claimed over 100 lives in over a month.