The group was targeting the interior ministry, the Saudi embassy and a causeway linking the two countries, it was said.
Hasan said the four men arrested in Qatar had been travelling by car from Saudi Arabia. Authorities seized "documents and a computer containing information of a security nature [and] details on certain vital sites," as well as dollars and Iranian riyals.
"They then confessed that they had left Bahrain illegally at the instigation of others and gone to Iran" to form an "organisation to commit armed terrorist acts in Bahrain," he added.
Sent back to Manama on November 4, they denounced a fifth accomplice, who was subsequently arrested, and the five have been turned over to the judicial authorities.