The group carried out serial blasts at over 600 locations in 63 districts in 2005 soon after the government banned it, killing at least two people and wounding over hundred others.
The additional district and sessions judge's court ordered 20 years in jail for the convicts. They have also been fined by Tk 30,000 (Rs 23,588) each, failing to pay which will make them stay in jail for another three years.
In 2012, police pressed charges in court against 17 JMB operatives, the bdnews24 reported.
Court police's Inspector Anwarul Islam said charges against three suspects were dropped as they had died while four of the convicts are absconding.
The group is also blamed by Bangladeshi authorities for a deadly attack on a Dhaka cafe in July last year that killed 22 people, mostly foreigners and an Indian woman.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)