A Dhaka court has handed down death penalty to 19 people, including two former ministers, and sentenced a top opposition leader to life imprisonment over a 2004 attack on the current Prime Minister Sheikh Hasina.
Minutes into Hasina's speech at the rally in 2004, assailants threw grenades that killed 24 people and wounded more than 500, a lot of them workers of her Awami League party, which was in the opposition at the time.
Hasina, now the prime minister of Bangladesh survived in the attack with a partial hearing loss.
Tarique Rahman, the fugitive son of Zia and presumed political heir, was the prime accused in the decade-old grenade attack case.
The grenade attack killed two dozen people and wounded about 300 others.
Security was stepped up in the country ahead of the verdict.
Police spokesman Sohel Rana said security was tightened in courts and across the South Asian nation to avert any violence following the verdict.
The 73-year-old Zia has been in a state-run hospital since Saturday receiving treatment for what her party says are multiple medical complications. At present, Rahman resides in London and is believed to have sought asylum.
Those to hang include a former minister and deputy minister, both leaders of the BNP party which was then in power.
The judge made 12-point observations on the background, motive and consequences of the attack.
Investigation found that an influential quarter of the then BNP-led government, including Rahman, masterminded and sponsored the attackers - operatives of Harkat-ul Jihad al Islami (HuJI).
Investigators said Ms Hasina was the main target of the attack. Among the dead was the wife of a former president.
Bangladesh Law Minister Anisul Huq welcomed the verdict and pledged he would try to bring the fugitives back, but the opposition immediately rejected the ruling.
Other political figures, who were given life sentence, are ex-premier Zia's the then political adviser Haris Chowdhury and former BNP lawmaker Qazi Shah Mofazzal Hossain Kaikobad.