A suicide car bombing today in Baghdad's Shiite militia stronghold, Sadr City, has killed at least 20 people.
Witnesses say the midday blast hit an Iraqi patrol about 300 yards from a U.S.-Iraqi security station. Iraqi police say as many as 48 others have been wounded.
The attack came asto talk about stabilizing the violence-shattered country.
The blast scattered burning debris across a small bridge, witnesses said.
An Associated Press reporter traveling with U.S. troops nearby said the explosion showered shrapnel across a joint U.S.-Iraq security station 300 yards away. The partially-shattered windshield of a car landed at the gates of the compound.
Home to about 2.5 million of Baghdad's poorest residents, Sadr City is the base for fighters allied to anti-American cleric Muqtada al-Sadr. His militia, the Mahdi Army, has laid low in recent weeks during a U.S.-Iraqi security crackdown under pressure from Iraqi Prime Minister Nouri al-Maliki.
Hours earlier, Iraqi special forces teams backed by U.S. soldiers detained six suspects believed to be a rogue members of the Mahdi Army, the U.S. military said in a statement.
The suspects were accused of coordinating and carrying out kidnappings and murders of Iraqi civilians, the statement said.
In central Baghdad, two mortars fell near Iraq's Foreign Ministry, where envoys gathered for an international conference on how to quell the violence and bolster Iraq's government. There were no reports of injuries, but smoke was visible from the meeting area.
Meanwhile, Iraqi officials said they were holding a top al Qaeda official, but not the terror mastermind Abu Omar al-Baghdadi who they believed was captured a day earlier.
"After preliminary investigations, it was proven that the arrested al Qaeda person is not Abu Omar al-Baghdadi, but, in fact, another important al Qaeda official," said Brig. Gen. Qassim al-Mousawi, an Iraqi military spokesman.
"Interrogations and investigations are still under way to get more information," he said.
Al-Mousawi declined to give the suspect's name on Saturday.
It was al-Mousawi who announced late Friday that al-Baghdadi had been captured. A senior adviser to the prime minister also had told the AP that al-Baghdadi had been taken into custody. The adviser spoke on condition of anonymity because he was not authorized to release the information.
Al-Mousawi said the suspect at first identified himself as al-Baghdadi, and that his identity was corroborated by another man captured with him. The reported arrest followed rumors this week that al-Baghdadi's brother had been arrested in a raid near Tikrit.
He is believed to lead the shadowy Islamic State of Iraq, an al Qaeda-inspired group that challenged the authority of Iraq's elected government. He has also signed militant messages posted online, as the leader of the Mujahedeen Shura Council — an umbrella group that includes al Qaeda in Iraq.
An alleged member of the Islamic State of Iraq was among 27 suspects detained in U.S. raids across Iraq overnight, the U.S. military said.
One suspect was killed and 18 were detained in Taji, an area on the northern outskirts of Baghdad, the military said in a statement.
Eight suspects were captured in Mosul, 225 miles northwest of Baghdad, and one was detained in Ramadi, 70 miles west of Baghdad, it said.
Also Saturday, the U.S. military said it was investigating the shooting of three Iraqis in Baghdad's Azamiyah neighborhood. American paratroopers fired on a vehicle when it failed to respond to warning signals, the military said in a statement. Three Iraqis were killed and three others were wounded in Friday's incident, it said.
In Other Developments:
Kidnap Victims Make Plea
An Iraqi insurgent group threatened to kill a German woman and her son kidnapped in Iraq unless Germany withdrew its troops from Afghanistan within 10 days, according to a video posted by the group on Saturday.
The video, from a previously unknown group calling itself the "Arrows of Righteousness," shows the abducted woman, identified as Hannelore Marianne Krause. She wears a blue scarf over her head, has eyeglasses and is shown seated on the floor, next to her grown son.
"I am here threatened by these people, they will kill my son in front of my eyes, then they will kill me if the German forces do not pull out of Afghanistan," she sobs, speaking in German as an Arabic translation scrolls over the screen.
The woman appeals to German Chancellor Angela Merkel to respond to the kidnappers' demands.
"Respectable Chancellor Merkel, I am terrified in this country as I have been detained for a long time," she says. "I beg you to do anything to appease these men."
The faces of the two captives are downcast. The son, a dark-haired younger man whom the woman holds on to, does not speak but bursts into tears.
Three masked gunmen also are shown in the video standing behind the hostages, holding Kalashnikovs and threatening to kill the two in 10 days if Germany did not give in to their demand.
German officials have refused to identify the captives or say why they are in Iraq.
The authenticity of the insurgent video, carried by the Arab stations, could not be independently verified.
Last month, German authorities confirmed that two Germans had been missing in Iraq since Feb. 6.
German newspaper Berliner Morgenpost had said the two apparently were kidnapped in Baghdad.
Germany has no troops in Iraq but has about 2,700 troops serving with the NATO-led International Security Assistance Force in Afghanistan, most of them focused in the north of the country.