Reports have surfaced that the leader of Al Qaeda in Iraq was killed by Sunni tribesmen, but the chief Iraqi government spokesman said Tuesday the information has not been confirmed and a major insurgent group denied the report.

A statement by spokesman Ali al-Dabbagh followed a welter of reports from other Iraqi officials that Abu Ayyub al-Masri, also known as Abu Hamza al-Muhajer, had been killed. Iraqi officials have released similar reports in the past, only to acknowledge later they were inaccurate.

"We will make an official announcement when we confirm that this person is Abu Ayyub al-Masri," al-Dabbagh told Al-Arabiya television. "The Iraqi government will work to identify him."

Sheikh Abdul Sattar Abu Risha, head of the regional anti-Al Qaeda group Anbar Salvation Council, claims fighters loyal to his group engaged in a two-hour battle with Al Qaeda members and that al-Masri was among them.

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Risha said that seven terrorists, including al-Masri and three other foreigners, were killed in the battle that took place between Tarmiyah and Samarra north of Baghdad. He said al-Masri's body was turned over to American forces who had arrived on the scene following the fighting.

The Islamic State of Iraq, an umbrella insurgent group, released the following Internet statement: "The Islamic State of Iraq reassures the Ummah [nation] that Sheik Abu Hamza al-Muhajer, God protect him, is alive and he is still fighting the enemy of God."

The statement was posted on a Web site commonly used by insurgents.

Lt. Col. Christopher Garver, a U.S. spokesman, said he could not confirm the reports, including a claim that U.S. forces had possession of the body in question.

"Obviously I hope it's true," Garver said, pointing out that previous Iraqi claims had proven false. "We want to be very careful before we confirm or deny anything like that."

U.S. Ambassador Ryan Crocker told reporters that American authorities in Baghdad were seeking more information.

A series of reports al-Masri had been killed, either by rivals in Al Qaeda or Sunni tribesmen who have turned against the terror group.

In recent months, opposition to Al Qaeda has sharpened, in part because of Al Qaeda's attempt to dominate the "resistance," impose a harsh brand of Islam on ordinary people and use foreign fighters, U.S. officials say.

More than 200 Sunni Arab sheiks in Anbar province are said to have decided to oppose Al Qaeda, with some coming together to form the Anbar Salvation Council. Sunni fighters claim to have killed dozens of Al Qaeda members in recent fighting.

Al-Dabbagh said that word of al-Masri's purported death was based on "intelligence information," adding that "DNA tests should be done and we have to bring someone to identify the body."

But he refused to say whether Iraqi security forces have the body, citing security restrictions.

Col. Gary Keck, a Pentagon spokesman, said he was aware of the reports from Iraq but had no confirmation.

"U.S. forces are working with Iraqi officials to determine if this is true," he said, adding that he did not know whether U.S. forces were at the site of the alleged killing.

Deputy Prime Minister Barham Saleh told The Associated Press that al-Masri was believed to have been killed Monday in the Taji area north of Baghdad.

"Preliminary reports said he was killed yesterday in Taji area in a battle involving a couple of insurgent groups, possibly some tribal people who have problems with Al Qaeda. These reports have to be confirmed."

Al-Masri, an Egyptian-born militant, took over leadership of the terror network and was endorsed by Usama bin Laden after Abu Musab al-Zarqawi was killed last June in a U.S. airstrike in Diyala province.

During a teleconference with reporters in Washington, the U.S. ambassador said al-Masri's death would be a positive development but played down suggestions it would have any immediate impact on Al Qaeda activity in Iraq.

"Clearly taking a major terrorist off the battlefield is an important thing and if we can confirm it, if this did happen, without question it would be a significant and positive development," Crocker said. "That said, I would not expect it to in any way bring to end Al Qaeda's activities in Iraq."

Complete coverage is available in FOXNews.com's Iraq Center.

The Associated Press and Anita McNaught contributed to this report.