A Manama court Sunday jailed four Shiites for life and sentenced six others to 15-year terms for forming an Iran-linked "terrorist cell" to mount attacks in Bahrain, a judicial source said.
The defendants were part of a group of 24 on trial, of whom 14 were acquitted.
The interior ministry announced in February that it had busted a "terrorist cell" which planned to carry out attacks on sensitive military and civilian sites as well as public figures.
Members of the group had been spying for Iran and its elite Revolutionary Guards, according to the charges, and had set up an armed organisation called Jaish al-Imam, or the army of the imam.
Since September 29, a total of 138 Shiites have been sentenced to prison terms of up to life, after King Hamad in August ordered stiffer penalties for "terror acts".
These include a minimum 10-year jail term for an attempted bombing. If such attacks cause casualties, the sentence can be life imprisonment or the death penalty.
A Shiite-led uprising to demand a constitutional monarchy in the Sunni-ruled state across the Gulf from Shiite Iran was crushed in March 2011.
But homemade bomb attacks have since been carried out, and Bahraini Shiites continue to demonstrate in villages outside Manama and frequently clash with police.
At least 89 people have been killed since the protests began, according to the International Federation for Human Rights.