Bahrain has been facing a wave of protests and revolts in recent months [Reuters]

Bahrain has broken up a cell that has been planning attacks in the Sunni-dominated Gulf kingdom battling a Shia-led opposition movement, the interior ministry spokesman says.

Four members of the cell were detained in Qatar and turned over to Manama, while a fifth Bahraini was arrested inside the country, General Tareq al-Hasan said on Saturday.

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.

Earlier this year, Bahrain's monarchy crushed pro-democracy protests, spearheaded by the Shia majority, with the help of troops from Saudi Arabia and the United Arab Emirates.

Twenty-four people died during the month-long crackdown, according to official figures from the capital Manama though the opposition says 40 people were killed.

Four protesters have since died in custody.