The voice denied the reported internal clashes among Sunni Arab militants in which Abu Ayyub Al Masri was said to have died.

‘What you hear in the news on satellite channels about fighting between us and Jihadist groups, or with our blessed (Sunni Arab) tribes is just lies and fabrication,’ the voice said.

‘It is a desperate attempt to divide the Jihadist ranks,’ it added.

Iraqi authorities said on Tuesday that they were investigating reports that Masri, known to Islamists as Abu Hamza Al Muhajer, had died in internal clashes among insurgent groups.

The US military said it could not confirm the death of the Al Qaeda commander, whose demise has been reported more than once in the past, and Iraqi officials acknowledged that they had not laid hands on Masri’s corpse.

The Islamic State of Iraq -- an Al Qaeda-led coalition of Sunni insurgent groups -- insisted Masri was still alive in an Internet statement posted on Tuesday and also denied the infighting.

But in a challenge to Al Qaeda, three rival Sunni Islamist insurgent groups announced that they were joining forces in a rival front to the Islamic State.

‘In order to confront local, regional, and international challenges, an agreement has been concluded between three groups, the Islamic Army in Iraq, the Army of the Mujahideen, and the Ansar Al Sunna to form a united front,’ the new group said in an Internet statement.