Baghdad: An Al Qaida front group in Iraq has confirmed the killing of its two top leaders but vowed in a statement that its members were not cowed by their death and would continue to fight.

"After a long journey filled with sacrifices and fighting falsehood and its representatives, two knights have dismounted to join the group of martyrs," the statement said. "We announce that the Muslim nation has lost two of the leaders of jihad, and two of its men, who are only known as heroes on the path of jihad."

The four-page statement by the Islamic State of Iraq was posted on a militant website early yesterday.

It concluded: "The war is still ongoing, and the favourable outcome will be for the pious."

The statement comes a week after Iraqi and US security forces raided a safe house near Tikrit, Saddam Hussain's hometown north of Baghdad, killing Abu Omar Al Baghdadi and Abu Ayoub Al Masri.

The Islamic State of Iraq is an offshoot of Al Qaida in Iraq. Al Baghdadi was its self-described leader and was so elusive that at times US officials questioned whether he was a real person or merely a composite of a terrorist to give an Iraqi face to an organisation led primarily by foreigners.

Their deaths were triumphantly announced last Monday by Iraqi Prime Minister Nouri Al Maliki. US Vice President Joe Biden called the killings a "potentially devastating blow" to Al Qaida in Iraq.

But four days later, officials believe Al Qaida struck back, bombing mosques, shops and the office of an influential Shiite cleric to kill 72 in Iraq's bloodiest day of the year so far. Al Maliki said the insurgents were fighting back after the deaths of their two leaders.