Prime Minister

"I would anticipate that the major combat engagements are over," Maj. Gen. Stanley McChrystal told reporters at a Pentagon briefing. He said U.S. forces are moving into a phase of "smaller, albeit sharper fights."

McChrystal said the number of daily air missions had dropped to 700 or 800 in recent days, down from about 1,000 or more a day. And Monday, he said, marked the last day that aircraft from all five aircraft carriers would fly missions over Iraq.

Plans were announced to scale back the American naval presence in the Persian Gulf by bringing home two carrier groups in the coming days.

The USS Kitty Hawk and USS Constellation could leave the Persian Gulf in the next several days, officials said. That would leave the USS Nimitz, which recently replaced the USS Abraham Lincoln, as the only remaining carrier group in the gulf.

Officials also said one of the two groups in the Red Sea, the USS Harry S. Truman or the USS Theodore Roosevelt, could depart soon.

Coalition fighting Monday against Iraqi targets in Tikrit, Saddam Hussein's hometown, was not as fierce as some expected. McChrystal said the Iraqi forces there lacked a "coherent defense."

Still, he cautioned against any suggestion that danger had passed for coalition forces.

Meanwhile, U.S. troops believe they have found 11 mobile chemical and biological laboratories buried south of Baghdad outside Karbala, a U.S. general said Monday. (Full story)

No chemical or biological weapons were found along with the labs, but soldiers recovered "about 1,000 pounds" of documents inside them, said Brig. Gen. Benjamin Freakley of the Army's 101st Airborne Division.

U.N. weapons inspectors in February "found nothing untoward" at an ammunition filling plant close to where the United States says troops have found the labs, a U.N. inspection team spokesman said Monday.

In February, U.S. Secretary of State Colin Powell told the U.N. Security Council that Iraq had mobile biological weapons labs on at least 18 flatbed trucks.

Disarming Iraq of its alleged weapons of mass destruction had been among the coalition's foremost goals entering the war, officials said. To date, there have been no confirmed discoveries of any such weaponry.

The "only significant combat action" Monday took place in Tikrit, the lone major Iraqi holdout, said Brig. Gen. Vincent Brooks of U.S. Central Command.

After heavy airstrikes and sporadic battles Sunday, coalition forces from the south, west and north moved early Monday into the center of the north-central Iraqi city, the hometown of the deposed Iraqi president.

The Marines met "lighter than ... expected" resistance, "isolating" Republican Guard units and taking over one of Saddam's largest and most elaborate palaces, Brooks said. (Full story)

Sporadic shelling, bombing and gunfire interrupted the quiet as U.S. forces rumbled through city, Time magazine reporter Paul Quinn-Judge told CNN.

By day's end, many Marines had switched to cleanup mode, setting up checkpoints and patrolling the city and its suburbs, said Time magazine reporter Michael Ware. Ware said people inside the city told him the vast majority of Saddam's family and forces