Updated

U.S. troops went on the offensive from the gates of Baghdad (search) to the Syrian border Tuesday, pounding Sunni insurgent positions from the air and supporting Iraqi soldiers in raids on mosques suspected of harboring extremists.

American and Iraqi forces launched the operations ahead of Ramadan (search), expected to start at week's end, in an apparent attempt at preventing a repeat of the insurgent violence that took place at the start of last year's Muslim holy month.

Clashes broke out in a string of militant strongholds from Fallujah, 40 miles west of Baghdad, northward along the Euphrates Valley (search) to the Syrian border town of Qaim — all major conflict areas.

Some of the sharpest exchanges took place in Hit, 90 miles northwest of Baghdad, where residents and hospital officials said U.S. aircraft attacked two sites, killing two people and wounding five. The U.S. command had no comment.

U.S. helicopters fired on a mosque in Hit on Monday and set it ablaze after the military said insurgents opened fire on Marines from the sanctuary. Scattered clashes were reported overnight, killing at least two Iraqis and wounding 15, hospital official said.

Insurgents attacked an Iraqi National Guard outpost east of Qaim Tuesday, the U.S. military said. The local hospital reported 15 to 20 people were killed.

Seventy miles west of Baghdad, Iraqi troops backed by U.S. soldiers and Marines raided seven mosques in the Sunni insurgent stronghold of Ramadi, arresting a locally prominent member of a clerical association and three other people. They also seized bomb-making materials and "insurgent propaganda" in the mosques, U.S. officials said.

In Baghdad, the Association of Muslim Scholars, a Sunni clerical group suspected of links to the insurgency, condemned the mosque raids as an example of alleged American hostility toward Islam.

"I think there is a religious ideology that drives the American troops," said the association's official spokesman, Mohammed Bashar al-Faydhi. "President Bush has said at the beginning of the war that this is a `crusade,"' he said, referring to the Christian attacks on Muslims in the Middle Ages.

Angry Ramadi residents accused the Americans of breaking down doors and violating the sanctity of mosques.

"This cowboy behavior cannot be accepted," said cleric Abdullah Abu Omar. "The Americans seem to have lost their senses and have gone out of control."

However, the raids followed a surge in insurgent attacks in Ramadi, and the U.S. command accused the militants of violating the sanctity of the mosques by using them for military purposes. Marine spokesman Maj. Francis Piccoli said U.S. troops provided backup for the Iraqi soldiers but did not enter the mosques.

In Fallujah, the focal point for Sunni resistance, residents reported explosions and clashes on the eastern edge of the city Tuesday afternoon. At least five people were killed and four wounded in the blasts, according to Fallujah General Hospital. The victims were reportedly traveling in a truck and two cars on a highway outside the city when they came under fire.

The U.S. command said the clashes began when insurgents in Fallujah opened fire on troops from the 1st Marine Expeditionary Force. After the rebels began firing mortars, the Marines called in air support, and a U.S. warplane "dropped a precision-guided weapon, eliminating the insurgent fire," the military said.

The renewed activity around Fallujah followed a pair of pre-dawn airstrikes, which the U.S. command said targeted hideouts and meeting places of the feared Tawhid and Jihad, the terrorist group responsible for numerous kidnappings and beheadings of foreign hostages.

One of the airstrikes flattened a well known Fallujah restaurant and the other destroyed a building in another part of the city. Five people were killed and two were wounded in the two attacks, hospital officials reported.

Tuesday's airstrikes in Fallujah were the first in four days and occurred as Iraqi officials were in talks with city representatives to restore government control, which disintegrated after the Marines ended a three-week siege in late April.

Since then the city has fallen under the control of hardline Islamist clerics and their armed followers, who defended Fallujah against the Marines. Both sides have said they were close to an agreement but that several details remain unresolved, including how Iraqi forces would enter the city.

The attacks appear to be designed partly to make life so hard for the civilians that they will turn on Tawhid and Jihad.

The terror group, led by Jordanian militant Abu Musab al-Zarqawi, claimed responsibility for an attack Monday against a U.S. convoy in Mosul that killed three people, including an American soldier. The claim was contained in a compact disc made available to Associated Press Television News that shows a U.S. military vehicle exploding and bursting into flames.

A U.S. official, speaking on condition of anonymity, said there are concerns within the U.S. government about a possible rise in insurgent violence around Ramadan, because of an upswing last year — when bombings and rocket attacks accelerated significantly in Baghdad and other areas at the beginning of the holy month.

Some militants believe they would win a special place in paradise by sacrificing their lives in a jihad, or holy war, during Ramadan, when Muslims say their sacred book the Quran was revealed to the Prophet Muhammad.

Defense Secretary Donald H. Rumsfeld and White House officials have said recently that they plan to use a mix of diplomacy and military force to try to regain control of dozens of key cities from insurgents before elections planned for January.

Last week, the government struck a deal with Shiite militiamen loyal to radical cleric Muqtada al-Sadr to lay down their weapons and allow Iraqi forces to take control of the Sadr City district of Baghdad.

On Tuesday, hundreds of al-Sadr's fighters from his Mahdi Army lined up at police stations to hand in weapons in return for cash. Some of the weapons appeared to be old, and it seemed unlikely that the Mahdi Army would surrender all its arms.

Still, officials hope the weapons handover will be the first step toward ending the Shiite rebellion, enabling the Americans and their Iraqi allies to focus on the more dangerous Sunni insurgency.

Once the weapons handover is completed this week, the government has pledged to start releasing al-Sadr followers who have not committed crimes and to rebuild the war-ravaged slum. Raids have also been suspended.