Bombs killed more than 60 
people and wounded more than 200 Sunday in Baghdad and the northern oil center 
of Kirkuk - a dramatic escalation of violence as U.S. and Iraqi forces crack 
down on Iraq's most feared Shiite militia. 
Prime Minister Nouri al-Maliki left Sunday for talks in Washington this week 
with President Bush to discuss sectarian violence, which has risen sharply since 
Iraq's national unity government took office two months ago.
A suicide driver detonated a minivan at the entrance to a bustling market in 
Sadr City, the capital's biggest Shiite district and stronghold of radical 
cleric Muqtada al-Sadr and his Mahdi Army militia.
At least 34 people were killed and 74 were wounded, the Iraqi army said in a 
statement. Eight more people died and about 20 were injured when a roadside bomb 
exploded two hours later at a municipal building in Sadr City about a half mile 
from the car bombing, the army said.
In Kirkuk, 180 miles to the north, a car bomb detonated at midday near a 
courthouse. The courthouse is located among a cluster of wooden shops and 
stalls, many of which burst into flames, engulfing the warren of crowded streets 
in roiling black smoke.
Twenty people were killed and 159 were wounded, police said. The tally of 
injured was so high because many people were trampled as panic swept shoppers, 
police said. Others suffered burns when the initial blast triggered secondary 
explosions in shops that sold chemicals and flammable liquids, police said.
Scenes at local hospitals were gruesome. Victims young and old lay bleeding 
on stretchers and gurneys, some of them scarred with horrific burns. Many lay 
unattended as doctors and nurses scrambled to care for the large number of 
wounded.
It was the fourth car bombing this month in Kirkuk, the center of Iraq's vast 
northern oil fields. Tensions have been rising in Kirkuk because the area's 
Arabs, Kurds and Turkomen all have rival claims to the region.
Also Sunday, the U.S. military announced that an American soldier assigned to 
the 1st Armored Division was killed the day before in Anbar province, a bastion 
of the Sunni-dominated insurgency.
The Sadr City car bombing was the second major suicide attack this month in 
the teeming slum district, where al-Sadr's Mahdi militiamen rule the streets. A 
July 1 suicide bombing in Sadr City was followed by a wave of reprisal killings 
of Sunnis.
Many Sunni politicians hold the Mahdi Army responsible for the wave of 
attacks against Sunnis that followed the Feb. 22 bombing at a Shiite shrine in 
Samarra. Al-Sadr's aides deny that the militia is doing any more than protecting 
Shiites from attacks by Sunni extremists including al-Qaida in Iraq.
So feared is the militia among Sunnis that many of them refer to any band of 
armed, masked Shiites as the Mahdi Army.
Hours before the Sunday blast, Iraqi troops and U.S. advisers launched raids 
in Sadr City and the mostly Shiite district of Shula, searching for suspected 
members of sectarian death squads, a U.S. statement said.
Two hostages were freed in the Sadr City raid, and two people were arrested 
in Shula, U.S. and Iraqi officials said.
U.S. officials made no mention of al-Sadr or the Mahdi Army in statements 
about the raids.
"We are not concerned with whom they are affiliated. We are only concerned 
with taking people responsible for these illegal acts off the streets and will 
continue to do so aggressively," U.S. military spokesman Lt. Col. Barry Johnson 
said.
However, it was clear that the U.S.-led coalition is stepping up pressure 
against the Shiite militia in a bid to reduce sectarian violence, which U.S. 
officials now consider a greater threat than the Sunni-led insurgency.
Last week, British troops arrested the commander of Mahdi Army forces in 
Basra, Iraq's second-largest city. On Saturday, U.S. and Iraqi troops killed 15 
fighters in a three-hour gunbattle around al-Sadr's office in Musayyib, 40 miles 
south of Baghdad. One Iraqi soldier was killed, the U.S. said. 
Local officials also said U.S. and Iraqi troops Saturday raided al-Sadr's 
office in Mahmoudiya, scene of reprisal killings since suspected Sunni gunmen 
killed 50 people, mostly Shiites, in a raid last week on a market. 
In Najaf, a senior al-Sadr lieutenant claimed the Americans want to crush the 
radical cleric's movement because he is the most prominent Shiite leader to 
oppose the U.S. military presence. 
"We are the only group that rejects the occupation because we are 
nationalists," said Jalil al-Nouri. "We are the only political group that 
rejects their presence in the country and we demand that they leave. We are to 
the point, and we are clear." 
Al-Sadr, scion of one of Shiite Islam's most prominent clerical families, led 
two uprisings against the Americans in 2004. The U.S. stopped short of capturing 
him under pressure from the Shiite clerical hierarchy. 
After a cease-fire, al-Sadr has emerged as a major political force. He 
controls a movement modeled after Hezbollah in Lebanon, running charities, 
clinics and an armed militia. Al-Sadr's followers hold 30 of the 275 seats in 
parliament and control five Cabinet ministries including health, transportation 
and agriculture. 
Although al-Maliki has pledged to disband the militias, he relies on al-Sadr 
for political support. The prime minister's Dawa party was founded by al-Sadr's 
father-in-law, who was executed under Saddam Hussein.