Bahrain's King Hamad has decreed tougher penalties for "terror acts", according to the official BNA news agency.
Under a new law, suspects convicted of bomb attacks will be sentenced to life imprisonment or to death in cases of casualties, BNA said on Thursday.
The minimum penalty for an attempted bombing is 10 years behind bars.
The crimes previously carried unspecified jail terms.
The Sunni-ruled Gulf Arab country has been the scene of a Shia-led uprising since 2011.
Suspects found guilty of "raising money for a terrorist organisation" will be handed jail terms ranging 10 years to life.
Authorities will also have powers to revoke the citizenship of anyone found guilty of committing or inciting an act of terrorism.
Tensions have been on the rise in the Shia-majority kingdom in the run-up to a major opposition demonstration called for mid-August.
Authorities have already decided to ban the protest and threatened to severely punish those who take part.
Hamad ordered on Monday the government to implement a parliamentary call for tough measures against what the authorities term a surge in "terrorism" linked to the protests.
Ban on rallies urged
At a special session requested by Hamad during a parliamentary recess, mostly loyalist MPs also recommended "a ban on gatherings and rallies" in the capital, Manama.
They called for emergency law to be declared in Bahrain if the need arose.
Amnesty International, the UK-based rights watchdog, said on Wednesday that the adoption of the amendments would "lead to further violations of Bahrain's international human rights obligations".
The Shia-led opposition has condemned the language used in the parliamentary debate as a "declaration of war on the people, as well as open threats and insults to beliefs".
But opposition groups insisted in a statement that the people's actions remain "peaceful," denouncing "propaganda to promote a security solution ... which violates international conventions".
The authorities report a growing number of shootings and bombings targeting police stations and patrols in mainly Shia villages outside Manama, blaming "terrorists" for the attacks.
A criminal court sentenced 12 protesters on Thursday to two years in prison each for taking part in "unlicenced protests" and targeting "police forces with Molotov cocktails," a judicial source said.
Eight of them were tried in absentia.
A car bomb on July 17 exploded outside a Sunni mosque, close to the royal court in Rifaa south of Manama, without causing any casualties.
There have since been three arrests linked the blast.