He was behind the Feb. 22 bombing of the Shiite shrine in Samarra.
BAGHDAD, Iraq (AP) -- Authorities on Sunday announced the capture of al-Qaida in Iraq's No. 2 leader, accusing him of "brutal and merciless" terror operations, including the bombing of a Shiite shrine that touched off the sectarian bloodletting pushing Iraq toward civil war.
Iraq's national security adviser said Hamed Jumaa Farid al-Saeedi, known as Abu Humam or Abu Rana, was arrested a few days ago as he hid in a residential building southwest of Baqouba.
The arrest has left al-Qaida in Iraq suffering a "serious leadership crisis," national security adviser Mouwafak al-Rubaie said. "Our troops have dealt fatal and painful blows to this organization."
He accused the terror suspect of supervising the creation of death squads and ordering assassinations, bombings, kidnappings and attacks on Iraqi police and army checkpoints. "The operations were brutal and merciless," al-Rubaie said.
What he did
Not much is known about al-Saeedi, but al-Rubaie said he was the second-most-important al-Qaida in Iraq leader after Abu Ayyub al-Masri. Al-Masri is believed to have taken over the group after a U.S. airstrike killed leader Abu Musab al-Zarqawi north of Baghdad on June 7.
Al-Rubaie said al-Saeedi was "directly responsible" for Haitham Sabah Shaker Mohammed al-Badri, an Iraqi whom authorities have accused of leading the Feb. 22 bombing against the Shiite shrine in Samarra, 60 miles north of Baghdad.
The attack inflamed tensions between Shiite and Sunni Muslims and triggered reprisal attacks that have killed hundreds of Iraqis.
Al-Saeedi's capture "will affect al-Qaida in Iraq and its operations against our people, especially those aimed at inciting sectarian strife," al-Rubaie said.
The U.S.-led coalition and Iraqi authorities have announced numerous arrests after al-Zarqawi was killed that officials claim have thrown al-Qaida in Iraq into disarray.
But rampant sectarian violence and other attacks have continued, with at least 20 Iraqis killed in bomb attacks and shootings Sunday.
4 U.S. troops killed
The U.S. military command announced that four U.S. troops had been killed -- two soldiers killed by a roadside bomb Sunday in Baghdad and two Marines in separate incidents Friday and Sunday in the volatile Anbar province, west of the capital.
The arrest of al-Saeedi came just over two months after Iraqi authorities announced that they had captured Yousri Fakher Mohammed Ali, a Tunisian also known as Abu Qudama.
"This is a very important development," Deputy Prime Minister Barham Saleh said on CNN's "Late Edition."
"Deliberate intelligence work, both by Iraqi forces as well as the multinational forces, have dealt a very severe blow to al-Qaida organization in Iraq," Saleh said. "It is also significant because this man is believed to have been responsible for the attack on the shrines in Samarra, which led to the sectarian violence that we have seen."
A senior coalition official told The Associated Press that coalition forces were involved in al-Saeedi's arrest but would not give details on what role they played.
The official, speaking on condition of anonymity because announcements were being made by Iraqi authorities, said al-Saeedi had been arrested along with three other people near Baqouba, 35 miles northeast of Baghdad. Al-Zarqawi was killed on the outskirts of Baqouba.
Al-Saeedi "claims to be responsible for more attacks than he can remember" and has been involved in the insurgency almost from its beginning three years ago, the official said.
Al-Rubaie said al-Saeedi gave information that led to the capture or death of 11 other top al-Qaida in Iraq figures and nine lower-level members. He said those arrested included non-Iraqi Arabs but would not give any further information for security reasons.
The arrest "will affect al-Qaida in Iraq and its operations against our people, especially those aimed at inciting sectarian strife," al-Rubaie said.
Tensions, meanwhile, rose in the north, after the president of the Kurdish region, Massoud Barzani, threatened secession on Sunday, two days after he ordered the Iraqi flag to be replaced with the Kurdish one, sparking harsh words in Baghdad.
"If we want to separate, we will do it, without hesitation or fears," Barzani said during an address to the Kurdish parliament.
Prime Minister Nouri al-Maliki issued a terse statement saying only the national flag should be hoisted throughout the country.
"The current Iraqi flag is the only one which must be hoisted on each bit of Iraq's land until a decision is adopted by the parliament according to the constitution," the statement said.
The Kurdish region gradually has been gaining more autonomy since the 2003 U.S.-led invasion, and Sunni Arabs fear the Kurds are pushing for independence.
In other violence across Iraq, according to police:
A bomb exploded at an accessories market in Khalis, 50 miles north of Baghdad, killing four people and wounding 21, including at least one child.
An overnight mortar attack east of Baghdad killed six people, including two children, and wounded 15.
A roadside bomb targeting a police patrol in eastern Baghdad killed two policemen and a civilian and wounded three policemen.
Copyright 2006 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.