The latest statement by Abu Bakr al-Baghdadi, who heads the Islamic State of Iraq, reveals a growing rift within al-Qaida's global network. It also highlights the Iraqi wing's determination to link its own fight against the Shiite-led government in Baghdad with the cause of rebels trying to topple the Iran-backed Syrian regime.
His statement surfaced as rockets rained down on a Baghdad camp housing Iranian exiles, killing three people in the latest sign of growing unrest inside Iraq.
In an audio message posted online, the speaker identified as al-Baghdadi insists that a merger he announced in April with Syria's Jabhat al-Nusra rebel group to create a cross-border movement known as the Islamic State in Iraq and the Levant will go on.
Al-Nusra is an al-Qaida affiliate that has emerged as one of the most effective rebel factions in Syria. Its head, Abu Mohammad al-Golani, has rejected the takeover attempt by al-Baghdadi.
"The Islamic State in Iraq and the Levant will continue," al-Baghdadi said. "We will not compromise and we will not give up."
Al-Qaida's global leader, Ayman al-Zawahiri, has tried to end the squabbling and bring the group's local affiliates back in line.
In a letter posted online by Qatar-based Al-Jazeera TV last Sunday, al-Zawahiri declared that the Islamic State in Iraq and the Levant will be abolished and that the Iraqi and Syrian groups would remain independent with al-Baghdadi and al Golani as leaders of their respective branches.
Al-Baghdadi is now defying that command. In his statement, he referred to "the letter attributed to Sheik al-Zawahiri," suggesting he was calling into question the authenticity of the letter.
"I chose the command of God over the command that runs against it in the letter," al-Baghdadi said.
He urged his followers to rise up against Shiites, Alawites, and the "Party of Satan" — a reference to the Iran-backed Lebanese militia Hezbollah, which has been sending fighters to Syria to fight alongside President Bashar Assad's regime. Assad comes from the Alawite sect, an offshoot of Shiite Islam.
It was not possible to independently confirm whether the speaker was al-Baghdadi, but the man's voice was similar to that of earlier recordings.
Charles Lister, an analyst at IHS Jane's Terrorism and Insurgency Center, said there are indications that Jabhat al-Nusra and the Islamic State in Iraq and the Levant are operating as distinct groups inside of Syria.
He described al-Baghdadi's defiance as "a potentially very damaging split within al-Qaida's senior leadership."
"Al-Baghdadi's statement underlines an extent of division between himself and Zawahiri but also with another al-Qaida affiliate," Lister said. "Fundamentally, al-Baghdadi appears to be acting according to his own interests, instead of those of his ultimate 'employer,' al-Qaida."
Violence has spiked sharply in Iraq in recent months, with the death toll rising to levels not seen since 2008.
Al-Qaida in Iraq is thought responsible for many of the car bombings and other violent attacks targeting the country's majority Shiites and symbols of the Shiite-led government's authority.
Iraq risks growing more deeply involved in the Syrian civil war raging across its western border. Iraqi border posts along the Syrian frontier have come under attack by rebels, and Syrian truck drivers and soldiers have been killed inside Iraq.
Iraqi fighters are moving across the border, with Sunni extremists cooperating with the rebels and Shiite militants fighting alongside government forces.
Also on Saturday, an Iranian exile group living in a camp near Baghdad airport reported multiple casualties when the compound, known as Camp Liberty, came under attack from rockets.
The group, the Mujahedeen-e-Khalq, is the militant wing of a Paris-based Iranian opposition group that opposes Iran's clerical regime and has carried out assassinations and bombings in Iran. It fought alongside Saddam Hussein's forces in the 1980-88 Iran-Iraq war, and several thousand of its members were given sanctuary in Iraq. It renounced violence in 2001.
Camp residents Kolthom Serahati and Javad Naghashan were killed and several others were wounded, according to the NCRI.
Several Katyusha rockets struck the area, according to Iraqi security officials. Police and hospital officials said an Iraqi was also killed, and that the wounded included at least nine Iranians and seven Iraqis. The officials spoke on condition of anonymity because they were not authorized to release the information.
Iraq's government wants the MEK out of the country, and the United Nations is working to relocate residents abroad. Several residents moved to Albania last month.
U.N. envoy Martin Kobler condemned the attack, which he said happened despite "repeated requests to the government of Iraq to provide Camp Liberty and its residents with protective measures." He urged U.N. member states to do more to help resettle the residents abroad.
There was no immediate claim of responsibility for Saturday's attack.
A similar deadly attack in February was blamed on Shiite militants. The head of one Shiite militia, the Mukhtar Army, later that month threatened further strikes on the compound.
In another attack, Sunni cleric Khalil al-Fahdawi was killed when a bomb stuck to his car exploded late the previous night near Ramadi, police said Saturday. The cleric has been a supporter of Sunni anti-government protests that have been raging for months and exacerbating sectarian tensions.