In the first significant arrival of troops by air, about 1,000 U.S. Army paratroopers dropped into Kurdish-held territory in northern Iraq Wednesday, opening Operation Iraqi Freedom's northern front.

Troops from the 173rd Brigade parachuted from low-flying jets onto an airfield less than 30 miles from the Turkish border. The move was part of a new U.S. action plan to take the northern part of the country, since Turkey wouldn't allow American troops to enter from there.

• Map: The War in Iraq

With the skies finally clear after two days of sandstorms, and good weather forecast for the next few days, U.S. commanders said allied forces would quickly intensify pressure on their adversaries.

"You'll certainly see us increase our activity in the coming hours, days, given the clearing weather," an official at U.S. Central Command said, speaking on condition on anonymity.

Jim Wilkinson, spokesman for General Tommy Franks said on Thursday that intelligence shows the Iraqi regime paramilitary force is seizing children from their homes and forcing the males must fight or face execution in the victinty of Najaf.

"Once again, we see the regime's terrorist tactics, where they bring the innocent onto the battlefield as they try to do anything to stay in power," he said.

Meanwhile, coalition warplanes bombed an enemy convoy fleeing the besieged city of Basra in the south, and sandstorms cleared to ease the advance toward Baghdad.

One week into the war, the possibility of a major battle loomed within 100 miles of Baghdad as another convoy -- this one made up of elite Republican Guard forces -- moved in the direction of American troops aiming for Saddam Hussein's seat of power.

But U.S. Central Command officials told Fox News that they didn't see a massive column of Iraqi Republican Guard troops moving south from Baghdad; instead they saw Republican Guard units "repositioning" and apparently readying for battle. The officials said it's routine defensive posture for units to reposition before a big battle.

Hundreds of miles to the south, the unchallenged bombing of Iraqi forces leaving Basra raised hopes that U.S. ground troops could soon enter the city, feared at risk for a humanitarian crisis.

The military developments unfolded as the first food aid convoy rolled into southern Iraq, greeted at the border by hungry children.

Aid for Basra and other parts of southern Iraq is supposed to come through the port of Umm Qasr, which has been captured by the allies. However, British commander Brian Burridge said Thursday that Iraqi mines have been discovered in the port, delaying the arrival of a ship carrying 200 tons of aid until mine-sweeping is completed.

Burridge also said during the U.K. Central Command briefing says that British forces have arrested "a senior Baath party official,", although they have not yet interrogated this official, and therefore cannot release any details.

With coalition forces massing to the south, west and now the north of Baghdad, the Iraqi regime kept much of the news from its own people. Instead, it emphasized a claim that two American cruise missiles had killed 14 civilians in Baghdad and wounded dozens more.

"This war is far from over," President Bush said in a quick trip to the Florida headquarters of U.S. Central Command, which is overseeing the war. Still, he said victory was only a matter of time, adding, "There will be a day of reckoning for the Iraqi regime, and that day is drawing near."

Bush later flew to the Camp David presidential retreat for a meeting Thursday with British Prime Minister Tony Blair, his partner in the Iraq invasion.

Swirling sandstorms that have hampered American units over the past two days abated early Thursday. The swarming dust had also been crimping the bombing campaign, although U.S. airstrikes did manage to knock out Baghdad television for several hours, and explosions were heard near the oil-rich city of Kirkuk in the north.

American forces moving toward Baghdad clashed with Iraqi troops outside Karbala, 50 miles southwest of the capital, under sunny skies Thursday. Small groups of Iraqi armored personnel carriers tested Army defenses but were hit by U.S. warplanes before getting within 10 miles of American troops.

Coalition troops were making their way toward the center of Iraqi power on several other routes.

Lt. Col. Thomas Collins, spokesman for the U.S. Army Southern European Task Force, confirmed that paratroopers were on the ground in northern Iraq, many of them elite Rangers.

"I can only tell you yes, they've gone in. They're on the ground," he said.

Other officials said tanks, other vehicles and supplies would be airlifted in behind them.

Combat planes from the USS Theodore Roosevelt gave cover for the deployment by pounding Iraqi ground troops and bunkers in northern Iraq, U.S. military officials said.

American commanders had hoped to move a large force into northern Iraq from Turkey. But the Turkish parliament refused to allow that, and the parachute drop was the beginning of an alternative plan.

Allied warplanes, as well as ground units, hit the column leaving Basra. A British military source, speaking on condition of anonymity, said the column included as many as 120 tanks and other armored vehicles.

Meanwhile, at least 25 Marines from Camp Lejeune were injured during house-to-house fighting that began Wednesday night in Nasiriyah, according to a television reporter traveling with the troops.

Keith Garvin, reporting live for WTVD Wednesday evening (about 2 a.m. in Baghdad), said intelligence reports indicated 2,000 Iraqi troops were advancing on the camp, and a two-hour fight with missiles and artillery ensued, ultimately augmented by aerial bombing, he said.

Garvin said some of the Iraqi fighters were using women as shields and had given guns to children.

"Unfortunately some of the children have been firing at our Marines and our Marines have been forced to defend themselves," he said.

The wounded appeared to be in addition to 15 Lejeune Marines who have been reported injured during the Iraqi conflict. Eleven Lejeune Marines have died, nine in combat in the Nasiriyah area and two in accidents.

In a sandstorm that grounded other aircraft, a few helicopters managed Wednesday to evacuate wounded Marines and Iraqi prisoners and civilians, including a toddler, to a little desert airstrip.

Some had lost limbs, some had been shot, all picked up on the road to Baghdad during fire fights with Saddam Hussein's military. But as they were loading the casualties, Iraqis kept shooting. The only reason they went ahead with the mission, the pilots said, was because children were involved.

U.S. Central Command also confirmed Wednesday that Iraqi fighters were using American military uniforms to commit acts against the Iraqi people and to "possibly attack U.S. forces."

Fox News' Greg Kelly, embedded with the 3rd Infantry Division, reported that members of the 3rd Infantry found some of their own uniforms with American name tags on them in a bunker that had been abandoned by some of Saddam's Fedayeen paramilitary fighters.

Security tightened after the discovery.

Another embedded reporter with another brigade in the 3rd Infantry said an Iraqi soldier wearing one of the division's uniforms was driving an oil truck toward the American troops when he was stopped. The reporter said he was rigged with explosives to blow up the oil truck in the midst of the troops.

Central Command said they were investigating the incidents.

The Pentagon's No. 2 general, Marine Gen. Peter Pace, said that Iraq has executed prisoners of war in the week since the war began. Pace, apparently referring to some of the U.S. Army troops captured Sunday by Iraqi forces in the city of Nasiriyah, said Iraqis had engaged in many atrocities in the six days since the war began.

Iraq, in turn, accused coalition forces of "kidnapping civilians, shackling them, and regarding them as POWs."

Irregular Iraqi troops have prevented British troops from entering Basra, Iraq's second-largest city and site of a reported uprising by local civilians against Saddam's defenders. International aid officials have repeatedly expressed fears of an outbreak of disease, given the interruption of power and water supplies.

Details were sketchy as well about Iraqi troop movements to the north. Some officials said a huge convoy of perhaps 1,000 vehicles and members of Saddam's elite Republican Guard were moving south, in the direction of Marines making their way toward the capital.

Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said a "few vehicles" were moving south toward Karbala, site of a major land battle on Tuesday. "They're being engaged as we find them," he said.

U.S. officials blame the Fedayeen units for much of the resistance that has hampered the American-led advance through Iraq, accusing them of faking surrender only to shoot Americans and enforcing discipline among regular Iraqi army troops who may be less willing to fight.

One Defense Department official said commanders were surprised by the Fedayeen's capability and military commanders were changing their tactics.

"We're going into a hunting mode right now," said Marine Lt. Col. B.T. McCoy in Iraq.

Iraqi officials said 30 civilians were injured, some badly, when two American missiles landed in a residential Baghdad neighborhood.

Associated Press Television News video showed bodies wrapped in plastic sheeting in the back of a pickup truck and streets that had flooded after water pipes ruptured. Flames rose above burning buildings, mixing with smoke from fires Iraqis have lit to try to obscure targets for American combat pilots.

American military officials issued a statement saying that civilian damage was "possible" after an aerial attack aimed at nine Iraqi surface-to-surface missiles. "The missiles and launchers were placed within a civilian residential area," it said.

The first sizable relief convoy rolled across the border toward the southern port city of Umm Qasr, laden with water, boxes of tuna, crackers, sweets and other food.

Children greeted the trucks as they rumbled into Iraq from Kuwait. Among them was a boy of about 10 who pointed to his mouth and shouted "Eat, eat."

In the border town of Safwan, the arrival of a relief convoy from the Kuwait's Red Crescent Society triggered fighting among young Iraqis, some shoeless and dirty, over the white boxes of supplies.

The Associated Press contributed to this report.