BAQUBAH, Iraq — The top U.S. general on the ground in Iraq warned Saturday that a surge in violence was likely in coming months as Iraq's new government began its full term in office.

Army Lt. Gen. Peter Chiarelli, commander of U.S.-led troops in Iraq, said that despite political progress and the growing competence of Iraqi security forces, troops are still fighting a bloody insurgency.

"There's nothing about this that I would [call] peacekeeping," he said. "We're in a fight."

At least 70 U.S. troops were killed in April, the highest toll in five months. A soldier died Saturday when his vehicle struck a roadside bomb southwest of Baghdad.

Chiarelli spent Saturday in Baqubah, about 35 miles northeast of the capital, addressing Iraqi and American troops. In recent weeks, rebels have mounted a series of bold, large-scale attacks in an effort to gain control of the ethnically and religiously mixed city, the capital of Diyala province.

On Thursday, rebels launched mortar rounds at an Iraqi army base and then simultaneously attacked four police stations. Up to 100 insurgents battled for hours with Iraqi security forces, using mortar launchers, rocket-propelled grenades and small arms.

Attacks came in waves throughout the day. One Iraqi soldier and 17 insurgents were killed, the U.S. military said, and U.S. commanders called in gunships to strike rebels hidden in orchards. There was sporadic fighting in Baqubah on Friday, but authorities then locked down the city, ordering a curfew that lasted until Saturday.

Despite the need for American backup, Chiarelli said, Iraqi soldiers and police officers fought side by side to fend off the rebels and stood their ground.

Traveling from his Baghdad headquarters to Baqubah in a phalanx of Black Hawk and Apache helicopters, Chiarelli was accompanied by several Iraqi generals, including the deputy commander of the Iraqi army, Lt. Gen. Nasier Abadi.

"By this heroic action, you have written a new chapter in the book of major exploits of the new Iraqi army," Abadi told soldiers from Iraq's 2nd Brigade, 5th Division. "You were able to conquer fear and uncertainty, and demonstrate how the will to win makes a difference in combat, leading to victory and defeat of the terrorists."

After the ceremony, Chiarelli addressed the team of U.S. military advisors who work to support the Iraqi soldiers. "Let us know if there's anything you need," he told the troops.

"Keep the helmets coming," answered Capt. John Wayne McFarlin. A sniper's bullet had hit his helmet during the gun battle and nearly pierced it.

"What we're seeing now, the upsurge in violence, is all about destabilizing the government," Chiarelli said in an interview as he traveled back to Baghdad. "It's a strategy to push up violence to take away the focus from what the prime minister is doing.

"I'll expect the violence to be high in the first months of the new government."

Parliament endorsed a deal on April 22 that designated Shiite politician Nouri Maliki as prime minister. He has 30 days from the time he was named to the post to put together a Cabinet, which will be Iraq's first permanent government since the 2003 U.S.-led invasion.

In the past, violence has surged around key political events such as elections.

"Zarqawi is starting to run out of events," said Chiarelli, referring to Abu Musab Zarqawi, the leader of Al Qaeda in Iraq.

Abadi, seated across from Chiarelli in the Black Hawk, likened a recent video message from Zarqawi to one of the last appearances by ousted Iraqi President Saddam Hussein before the invasion of Baghdad. Hussein stood atop a car, telling the crowd not to surrender.

"That was his grandstand, and it went to the pits after that," Abadi said. The appearance by Zarqawi, firing a machine gun, was intended "to show might, to show power," he said. "We have the same pattern repeating itself."

Chiarelli's comments echoed those of President Bush, who in his weekly radio address from Washington on Saturday warned of "more days of sacrifice and struggle."

The American casualty count in April, more than twice the previous month, broke a downward trend begun in November. Most of the toll came in Baghdad and volatile Al Anbar province, the western area that is the heart of the Sunni Arab-led insurgency.

Authorities in Baghdad said they found five bodies on Saturday, and two roadside bombs injured five police officers.

Six bodies were found in Dora, on the southern edge of the capital. All of the victims had been handcuffed and blindfolded, and showed signs of torture.

Near Tall Afar in northwestern Iraq, hospital officials reported that an adult and two children were killed when a mortar round hit their house. In Ramadi, clashes continued between U.S. troops and rebels. A number of rockets hit the provincial government building downtown, police said. There were no reports of casualties.

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