Bahrain's lower court jailed 10 Shiite men to life terms on Tuesday on charges of plotting attacks a day after the Gulf state sentenced 19 others to lengthy prison terms.
Three were sentenced in absentia after fleeing to Iran, Ahmad al-Hamadi, head of the counter-terrorism prosecution, said in a statement on Twitter.
A judicial source told AFP all those convicted were Shiite Muslims.
The 10 were also stripped of their Bahraini citizenship, Hamadi said.
They had been charged with forming an outlawed group that plotted "terror" attacks, smuggling arms and ammunition into Bahrain, travelling to Iran and Iraq for military training and possessing arms and ammunition.
On Monday, 19 Shiites were given lengthy jail terms after being convicted of spying for Iran and plotting to overthrow the regime.
Eight were given life terms, nine got 15 years and two received 10 years for espionage and inciting public dissent, a statement from the counter-terrorism prosecutor's office said.
Fifteen of those convicted on Monday were also stripped of Bahraini citizenship, the statement said.
Dozens of Bahrainis have been jailed and stripped of citizenship since the 2011 outbreak of protests demanding an elected government in the Sunni-ruled kingdom.
A key US ally and home to the US Fifth Fleet, Bahrain has tightened its grip on dissent, drawing harsh criticism from international rights groups for its treatment of the Shiite-majority population.
In April, parliament gave approval for military courts to try civilians charged with "terrorism", a vaguely defined legal term in Bahrain.
Manama accuses Shiite Iran of training "terrorist cells" that aim to overthrow Bahrain's government, an allegation Tehran denies.
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