An Al Qaeda militant group in Iraq on Wednesday claimed responsibility for a series of deadly bomb and gunfire attacks across Iraq on Monday that killed and wounded hundreds of Iraqis.

The self-styled Islamic State of Iraq (ISI), an Al Qaeda front in the country, confirmed in a statement posted on an Islamic website that its fighters carried out coordinated attacks to hit military and managing centers for the Iraqi Shiite-dominated government and its allies from Sunnis.

The attacks were the first wave of the "breaking the walls" plan, which was announced earlier by al-Qaida top leader in Iraq Abu Bakr al-Baghdadi, the statement said.

"The coordinated jihadist operations have stunned the enemy and made him lost his mind, and showed the failure of intelligence and security plans which filled the world with noise and bluster," said the statement, the authenticity of which could not be immediately verified.

On Sunday, al-Baghdadi announced that his militant groups would launch a new wave of violence particularly with the aim at releasing Al Qaeda prisoners and targeting the country's judges and investigators.

"We are starting a new stage of our struggle with a plan named 'breaking the walls'," said an audio massage purportedly made by al-Baghdadi, who was chosen as the head of the ISI in May 2010, after the killing of the previous two top Al Qaeda leaders Abu Ayyub al-Musri and Abu Omer al-Baghdadi in a military operation by Iraqi and US forces on April 18, 2010.

Al-Baghdadi said the priority of his plan is to free the " Muslim prisoners, chasing and eliminating judges and investigators and their guards."

He urged the Sunni tribal leaders to send their men to join Al Qaeda as the group is returning to its previous strongholds. His militant groups evacuated from the strongholds after the Iraqi anti-US Sunni insurgent groups turned their rifles against Al Qaeda network as the latter exercised indiscriminate killings against both Shiite and Sunni Muslim communities.

"On the occasion of the return of the Islamic State to the regions that had been evacuated, I urge you to send your sons to join the mujahideen (holy warriors) to defend your religion and honor," al-Baghdadi said in his message.

One day after al-Baghdadi's message, Iraq witnessed one of its deadliest days when a slew of bomb and gunfire attacks hit cities across the country, killing at least 80 people and wounding more than 280.

Such deadly attacks apparently are seen as an attempt by the insurgent groups to stir up sectarian strife among Iraqis to push the country to the brink of a civil war, amid persistent political divisions that have already paralyzed the country's government and its security services.