BAGHDAD, Iraq, AP -U.S. and Iraqi troops trying to stem the flow of insurgent fighters across the Syrian border launched a dawn assault Monday on another border town, killing a reported 37 insurgents.
Elsewhere, police in Baghdad said a car bomb detonated near one of their patrols outside a gate leading into the fortified Green Zone, killing three people.
Operation Steel Curtain entered a new phase Monday when U.S. and Iraqi forces moved into the Euphrates River valley town of Obeidi, 185 miles west of Baghdad.
"Five targets were struck by coalition air strikes resulting in an estimated 37 insurgents killed. The insurgents were engaging coalition forces with small arms fire at the time of the strikes," a U.S. military statement said. "Preliminary reports indicate an estimated 25 insurgents have already been captured and are currently detained."
The troops assigned to the 2nd Marine Division have already fought their way through two neighboring towns, Husaybah and Karabilah. U.S. forces believe the border towns have been an entry point for insurgent fighters and weapons into Iraq.
The explosion in Baghdad was followed by small arms fire and billowing black smoke that could be seen across the city. The blast killed three people and wounded two, interior ministry Maj. Falah al-Mohammadawi said.
He did not further identify the victims. The blast apparently targeted a convoy of sport utility vehicles leaving the Green Zone, the headquarters of the Iraqi government and U.S. forces in Iraq. The blast occurred near the Iranian embassy, about 100 yards north of the Green Zone gate.
The U.S. command, meanwhile, announced Sunday the deaths of three more U.S. troops.
The offensive in Obeidi followed demands by Sunni Arab politicians for an end to U.S. and Iraqi military operations, claiming they threaten Sunni participation in next month”s elections — a key U.S. goal.
U.S. commanders have said offensives, especially those in the western province of Anbar near the Syrian border, are aimed at encouraging Sunni Arabs to vote in the Dec. 15 parliamentary elections without fear of intimidation by insurgents opposed to the political process.
However, several major Sunni Arab political groups insisted Sunday that such operations risk keeping Sunni turnout low because civilians are displaced by the fighting or they will be too frightened to venture out to the polls.
Some alleged the Shiite-led government was intentionally carrying out operations northeast of Baghdad to discourage Sunni Arabs from voting — a charge that Iraqi officials have denied.
"We strongly condemn the military operations and demand that they are halted immediately," Saleh al-Mutlaq of the Sunni National Dialogue Front told reporters. "We demand that the United Nations, the Arab League and humanitarian organizations stop these massacres."
Ayad al-Izi, a member of the largest Sunni Arab party, charged that raids by the Interior Ministry in religiously mixed Diyala province were politically motivated to cow Sunnis.
"Such practices are aimed at foiling the political process in the country and they ignite the strife in such areas," said al-Izi of the Iraqi Islamic Party.
The Interior Ministry said 310 people were arrested in the Diyala raids, which followed a truck bombing in a Shiite village that killed about 20 people. It did not say whether all those arrested were Sunnis.
In a statement Sunday, the U.S. command said two Marines were killed the day before by a bomb west of Baghdad and an American soldier died in a vehicle accident in western Iraq. The latest deaths brought to at least 2,065 the number of U.S. military personnel who have died since the war began in 2003, according to an Associated Press count.
Despite the rising casualty toll, U.S. officials have been encouraged because so many Sunni Arab groups have decided to run in the December elections, hoping that will induce members of the Sunni-dominated insurgency to stop fighting. That would allow U.S. and other coalition troops to begin heading home next year.
Most Sunni Arabs boycotted the Jan. 30 elections, enabling the majority Shiites and their Kurdish allies to dominate the current parliament. That in turn ratcheted up sectarian tensions and reprisal killings.
Many Sunni politicians now consider the January boycott a disaster for their community. But Sunni hard-liners — including insurgents and many clerics — remain adamantly opposed to the political process.
In other violence:
• In the western town of Ramadi, a Sunni stronghold, a roadside bomb detonated shortly after a U.S. patrol passed by, destroying two buses and killing five civilians and wounding 20 others, police Capt. Nassir Al-Alousi said.