The Court of Cassation upheld capital punishment for one defendant, a life sentence for a second, and lengthy prison terms for six others, according to a statement by the public prosecutor's office.
All eight have also had their Bahraini citizenship revoked.
A judicial source close to the case said the defendants were Shiites, who form the majority of the population in the Sunni-ruled monarchy.
The 2016 bombing, in the eastern village of Sitra, targeted a police patrol, authorities said at the time. The casualties, however, were civilians -- a woman was killed and her three children wounded.
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Authorities say two of them are still on the run.
Located between regional rivals Sunni-ruled Saudi Arabia and Shiite-led Iran, Bahrain has been the site of Shiite-led protests demanding an elected government since 2011.
Bahrain's rulers accuse Iran of backing the protesters and inciting unrest in the kingdom, a charge Tehran denies.
Authorities have cracked down on all dissent, drawing harsh condemnation from international rights groups.
They have jailed dozens of high-profile activists, disbanded both religious and secular opposition groups and -- according to Amnesty International -- rendering hundreds stateless by stripping them of their citizenship and rendering them stateless.
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