Interior Ministry says investigation has dismantled a number of terrorism operations in the kingdom
Bahraini authorities said on Tuesday they had arrested 28 people who had been planning terrorist operations in villages in the Gulf island kingdom.
The interior ministry did not name the detainees, say when they were held or elaborate on the nature of the planned attacks.
Bahrainis accused in the past by the Sunni Muslim-led government of planning and launching attacks have included opposition activists from the majority Shi'ite community.
"The investigation interrupted and dismantled a number of terrorist operations planned in various villages," state news agency BNA quoted the ministry as saying.
"The investigation included the tracking of individuals and the monitoring of their safe houses," it added.
The ministry said some of those detained had already been convicted on terrorism charges in absentia and had been sentenced to life terms in jail, while others had had their citizenships revoked.
The Sunni Muslim royal family used martial law, backed up by military intervention from some other Gulf Arab forces, to quell a Shi'ite-led uprising in 2011, but unrest has simmered.
Shi'ites in the kingdom complain of discrimination and police brutality, but authorities say they have implemented reforms. Demonstrations have increasingly given way to bomb attacks on the security forces, which have killed several members of the security forces.
Bahrain, where the U.S. Fifth Fleet is based as a bulwark against Shi'ite Iran, accuses Tehran of encouraging the unrest and has promised a tough response as talks with the opposition have stalled. Iran has denied meddling in Bahrain's affairs.