Baghdad, Iraq (CNN) Izzat Ibrahim al-Douri, a former top deputy to Saddam Hussein and more recently a key figure in Sunni extremist groups battling the Iraqi government, has been killed in a security operation in that country, Iraqi state-run television reported Friday.

Al-Douri was the highest-ranking member of Hussein's regime to evade capture -- the "King of Clubs" in a deck of playing cards used by American troops to identify the most-wanted regime officials

He also was a man thought to have led the post-Hussein Sunni extremist group Naqshbandi Army. Military analysis website Globalsecurity.org says the Naqshbandi Army supports ISIS , which has taken over parts of Iraq and Syria

Al-Douri was killed in an operation by Iraqi security forces and Shia militia members in the Hamrin Mountains between Tikrit and Kirkuk, Iraq, Shia militia commander Hadi al-Ameri said.

That militia is a predominantly Shiite fighting group that worked with Iraqi troops earlier this month to liberate the Iraqi city of Tikrit from ISIS.

The death of al-Douri was also reported by the governor of Salahuddin province, Raid al-Jubouri, who spoke by phone on Iraqi television.

Al-Douri's body arrived Friday in Baghdad, where DNA samples were taken to confirm the identity, said the spokesman of another Shiite militia called Hashd Shaabi in an interview with state-run Iraqiya TV.

DNA test results could be available in 48 hours, Hashd Shaabi spokesman Yousuf al-Kilabi told the outlet.

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The U.S. military is aware of the media reports but doesn't have further information to evaluate them, said Col. Patrick Ryder, spokesman for U.S. Central Command.

While officials are aware of al-Douri's role in the Hussein regime, Ryder declined to comment about whether the United States or the coalition was targeting any specific individuals.

"Shut up...you monkey"

Al-Douri was a military commander and vice chairman of the country's revolutionary command council in Hussein's Sunni-dominated regime -- effectively Hussein's No. 2 man.

Hussein's regime fell during a U.S.-led invasion in 2003. The U.S. military had said that after the Iraqi leader's fall, al-Douri helped finance a Sunni insurgency with money he transferred to Syria before the government collapsed.

A month before the invasion, al-Douri presided over a military parade in Mosul, an event covered by CNN, and his participation became one of the last times he was seen in public, covered by CNN.

Al-Douri saluted troops from the reviewing stand as they marched by.

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Then, just days before the U.S. invasion, al-Douri addressed an emergency summit of the Organization of the Islamic Conference to discuss ultimately unsuccessful ways to avert the war.

Al-Douri accused the United States of aggression and blamed Kuwait for his country's suffering, calling leaders of the neighboring Gulf state "traitors" for cooperating with the United States and Israel.

Kuwaiti television cut away from the heated exchange and rejoined the conference later.

2012 videos purportedly of al-Douri

In subsequent years, several claims asserted that al-Douri was either killed or captured during the war and its aftermath. At the same time, a man claiming to be al-Douri released a number of audio messages over the years taunting Iraqi and U.S. officials.

In 2012, a series of videos appeared online purporting to show al-Douri deriding the Shiite-led government that took over Iraq after Hussein's ouster.

CNN couldn't independently verify the authenticity of those videos on YouTube or the identity of the man speaking, though he bore a striking resemblance to al-Douri.

In the clips, the man who claimed to be al-Douri wore an olive military uniform and sat behind a desk with an Iraqi flag in the background.

Photos: Iraq War: Top 8 most wanted Photos: Iraq War: Top 8 most wanted King of Clubs – Izzat Ibrahim al-Douri

Revolutionary Command Council vice chairman / Northern Region commander / Deputy secretary general, Ba'th Party Regional Command / Deputy commander, Iraqi armed forces.

April 17, 2015: killed in a security operation in Iraq, according to Iraqi state-run television. Hide Caption 1 of 8 Photos: Iraq War: Top 8 most wanted Ace of Spades – Saddam Hussein

Former Iraqi President

December 13, 2003: Captured in a "spider hole" in Tikrit.

November 5, 2006: Sentenced to death.

December 30, 2006: Executed. Hide Caption 2 of 8 Photos: Iraq War: Top 8 most wanted Ace of Clubs – Qusay Hussein

Saddam Hussein's second son

Chief, Special Security Organization / Special Republican Guard; Commander, Central Region Commander

July 22, 2003: Killed in firefight in Mosul. Hide Caption 3 of 8 Photos: Iraq War: Top 8 most wanted Ace of Hearts – Uday Hussein

Saddam Hussein's eldest son

Member of the National Assembly, Olympic Committee

July 22, 2003: Killed in a firefight in Mosul. Hide Caption 4 of 8 Photos: Iraq War: Top 8 most wanted Ace of Diamonds – Gen. Abed Hamoud Mahmud al-Tikriti

Saddam Hussein's personal secretary and senior bodyguard

June 18, 2003: Captured and later convicted and sentenced to death.

June 7, 2012: Executed. Hide Caption 5 of 8 Photos: Iraq War: Top 8 most wanted King of Spades – Ali Hasan al-Majid

Revolutionary Command Council / Commander, Ba'ath Party Regional Command / Head Of Central Workers Bureau

August 21, 2003: Captured and sentenced to death in four separate trials.

January 25, 2010: Executed. Hide Caption 6 of 8 Photos: Iraq War: Top 8 most wanted King of Hearts – Hani abd al-Latif al-Tilfah al-Tikriti

Director, Special Security Organization / Responsible for security and investigations

Still at large. Hide Caption 7 of 8 Photos: Iraq War: Top 8 most wanted King of Diamonds – Aziz Saleh Al-Numan

Ba'ath Party regional command chairman

May 22, 2003: Captured and later convicted and sentenced to death.

July 16, 2011: Transferred from U.S. custody to Iraqi custody. Hide Caption 8 of 8

He derided Iraq's Shiite-dominated government, led by then-Prime Minister Nuri al-Maliki, as well as what he described as meddling by neighboring Iran. Al-Maliki's Dawa party, says al-Douri, "has announced Iraq as the Shiite capital."

At that time, nine years had passed since the invasion and, al-Douri claimed that Iraq was still in peril.

"Everyone can hear the sounds of danger echoing daily and threatening the country," he said.

The videos were posted on what was the 65th anniversary of the Arab Socialist Baath Party, a political party founded in Syria that later provided the political basis for Hussein's now outlawed Baath Party.