Bahrain said Saturday that it had arrested 25 suspects accused of involvement in unrest in the Sunni-ruled kingdom, including a deadly jailbreak.
The authorities said they were part of a "terrorist organisation" that includes 54 members, some of them fugitives in Iraq and Iran -- accused repeatedly by Manama of meddling in its internal affairs.
The alleged members include 10 former inmates who escaped in the January 1 storming of Jaw prison, Bahrain's general prosecutor Ahmed al-Hammadi said in a statement carried by state news agency BNA.
One of them was shot dead last month along with two men as they allegedly tried to flee the country by boat.
Bahrain has been shaken by unrest pitting its Shiite-majority population against its Sunni Muslim rulers.
A 2011 uprising seeking a constitutional monarchy and an elected prime minister was crushed with deadly force.
The Shiite opposition has since been banned and many of its leaders given long jail terms, several of them on "terrorism" charges.
The 25 detainees have been charged with "joining a terrorist organisation" and "training on using explosives and firearms to commit terror attacks," Hammadi said.
They are also accused of killing two police, including one during the January 1 jailbreak, and the attempted murder of others, as well as importing and possessing explosives and firearms.
The suspects were also accused of escaping from jail or helping others to flee and hide.
The statement said four suspects denied the charges, while the rest confessed to being guilty.
Police found "large quantities of explosives, detonators and hand grenades," in addition to four AK-47 assault rifles and seven pistols, the statement said.
One of the suspected members of the organisation lives in Germany and has "arranged travel for members of the organisation to Iran and Iraq to train on using explosives and machine guns," Hammadi said.
He said the training took place in the bases of Iran's Revolutionary Guards with the aim of "preparing to carry out terrorist crimes inside the country."
Twelve fugitives remain in Shiite-dominated Iran and Iraq, the statement said.
Bahrain, home to the US Fifth Fleet, repeatedly accuses Iran of fanning unrest in the strategic archipelago. Tehran insists it is merely speaking in defence of the rights of Shiite Muslims.