Al Qaida in Iraq has vowed to carry out "100 attacks" across the country, starting in the middle of the Muslim holy month of Ramadan, to exact revenge for the death of Osama bin Laden.

The terror group's statement was released on militant websites late yesterday.

It said the attacks will avenge bin Laden, who was killed by US forces in Pakistan in May, and other slain senior al Qaida leaders.

"By God's will, the campaign starts in the middle of the fasting month (of Ramadan) and ends by God's will after 100 attacks exactly," it said.

The statement said the campaign would include "varied attacks, including raids, martyrdom operations, roadside bombs, silenced guns and snipers, in all cities, rural areas and provinces" across Iraq.

Monday marked the middle of Ramadan.

On that day, a wave of attacks swept across Iraq - from the northern city of Mosul to the southern Shiite heartland.

At least 70 people died in suicide bombings, roadside bombs and shootings in what was Iraq's deadliest day this year.

Al Qaida did not explicitly claim responsibility for those attacks in the statement, but the chaos is widely believed to be the work of al Qaida in Iraq.

A little over a year ago, US and Iraqi officials said the deaths of al Qaida in Iraq's two top leaders in a raid had dealt a severe blow to the organisation.

The group has suffered from a drop in funding and just two weeks ago was calling on former members to come back to the fold, a sign of its diminished status.

But Monday's violence suggests that al Qaida in Iraq has the ability to resurrect itself and still carry out vicious attacks.