BAGHDAD: Al Qaeda's Iraq front group claimed a wave of attacks that killed 113 people on Monday in Iraq's deadliest day in two and a half years, saying it marked the launch of a new campaign promised by its leader.

“The operation by the jihadists has stunned the enemy and made him lose his head. It has demonstrated the failings of the security and intelligence services,” the Islamic State of Iraq (ISI) said in a statement posted on jihadist website Honein.

Last weekend, the group said it would begin targeting judges and prosecutors, and try to help its prisoners break out of Iraqi jails, in an Internet audio message purportedly left by its leader Abu Bakr al-Baghdadi.

The message posted on various jihadist forums said the ISI would look to retake territory, and appealed for Sunni tribes to provide support and send fighters.

“We are starting a new stage,” said the voice on the audio message, purportedly that of Baghdadi, who has been leader of ISI since May 2010.