Al-Qaeda's front group called on Iraq's Sunni population on Thursday to take up arms against the Shiite-led authorities and dismissed the country's Sunni ministers as weak and corrupt.

An audio message, purportedly read by Islamic State of Iraq spokesman Abu Mohammed al-Adnani, encouraged the minority community to continue with weeks of demonstrations but said Sunnis would not gain dignity without bloodshed.

It came as the group issued statements claiming 82 attacks on security forces and government officials from October 17 to December 12 south and west of Baghdad.

"You have two options," Adnani said in the message posted on a jihadist Internet forum. "You can kneel to them (the government), and this is impossible, or carry weapons and you will be the superior."

He continued: "Obtaining dignity and freedom, and rejecting oppression, will not happen one day without the raining of bullets and blood."

"This is a tax; we have to pay it for our dignity. The tax of being subjects and humiliation is much heaver than this."

"Continue with your blessed demonstrations, and prepare to hold weapons, which the apostate will force you to carry... Only at that time will we restore our dignity."

Weeks of protests in Sunni-majority areas of the north and west have railed against the alleged targeting of their community by the Shiite-led authorities and have, more recently, called for Prime Minister Nuri al-Maliki to resign.

The rallies were sparked by the December 20 arrest of at least nine guards of Finance Minister Rafa al-Essawi, a top Sunni leader.

In a major escalation of tensions, eight demonstrators were killed by troops last week in Fallujah, west of Baghdad, the first deaths of protesters at the hands of security forces since the rallies began.

Thursday's message also dismissed Sunni ministers in Maliki's national unity government as corrupt and self-serving, saying "your politicians did not get angry even once for the violations against you."

"The Safavid government remained his political partner," Adnani said, in an apparent reference to Sunni ministers as one.

He also made a pejorative swipe at the Shiite-led government, implying that it was under the domination of neighbouring Shiite Iran, ruled by the Safavid dynasty from the 16th to 18th centuries.

"Until (the Safavid government) turned against him, and the fire of the Safavids touched his post... At that time (the Sunni ministers say) the government becomes sectarian and unfair... and call upon the people to rise against it."

Adnani also dismissed a recent cross-sectarian gesture by powerful Shiite cleric Moqtada al-Sadr, who joined with Sunni leaders to pray together at a major Sunni mosque in Baghdad.

"Those apostates who have not revealed their intentions are more dangerous," said Adnani, describing Sadr as "mentally challenged."