BAGHDAD, Iraq -- The United States launched an anticipated, ferocious, around-the-clock aerial assault on military targets in Baghdad and other cities Friday, and invading ground troops penetrated 100 miles into Iraq. The ancient capital's skyline exploded in balls of flame, leaving Saddam Hussein's Old Palace compound and other symbols of his government ablaze.

Another huge explosion shook the center of Iraq's capital before dawn today.

U.S. intelligence officials said the Iraqi command and control system was in disarray, and Defense Secretary Donald H. Rumsfeld said, "The regime is starting to lose control of their country."

The aerial onslaught, dubbed a campaign of "shock and awe," was designed to accelerate that.

The U.S. Central Command, which is running the war, said the targets included military command and control installations and buildings in and around Baghdad, as well as targets in the northern cities of Mosul, Kirkuk and Tikrit, Saddam's hometown.

One senior defense official said U.S. and British warplanes flying from more than 30 bases would fly about 1,500 strike missions during the first 24 hours of the accelerated campaign. Plans called for the launch of nearly 1,000 Tomahawk cruise missiles from the Persian Gulf and Red Sea.

Early today, aircraft could be heard overhead, but it was unclear what had been targeted. Following the single blast, sirens presumably from ambulances or police cars could be heard racing through the city.

The blast at first light shattered the eerie silence that had fallen over Baghdad after the rain of missiles Friday evening.

The barrage, which began just after 9 p.m., filled the sky with towering fireballs as the Tomahawk missiles hit and air raid sirens squealed. At one point, a half-dozen adjoining plumes of smoke twisted into the sky.

Allied ships in the Persian Gulf and Red Sea fired 320 Tomahawks in the largest strike since the war began. Two Iraqi palaces were among the buildings destroyed by the third missile attack on the city in two days.

The attack was apparently coordinated to simultaneously strike against Baghdad and two other cities, Mosul and Kirkuk in the north. The Iraqi defense minister, speaking as the missiles fell, said the coalition was also targeting the southern cities of Basra and Nassiriyah.

The air barrage came with U.S. ground troops already a third of the way to Baghdad, and with Saddam and his regime fighting to demonstrate their control of the country despite reports of surrendering Iraqi troops and the loss of strategic sites.

The spectacular blasts lit up the horizon, illuminating Baghdad even as they devastated parts of the city of 5 million people. In response, the Iraqis opened up with anti-aircraft bursts that winked in the darkness. At one point, the sound of a missile roared through a street before exploding into a fireball.

Old Palace burning

Three major fires raged inside Saddam's Old Palace compound, which stretches for 1.7 miles on the west bank of the Tigris River. The compound is the official center of the Iraqi state, and home to the offices of the prime minister's staff, the Cabinet and a Republican Guard camp.

Its turqoised-domed main building appeared untouched. But a building next to the palace was on fire, and black smoke billowed from a 10-story building in another part of the compound.

Information Minister Mohammed Saeed al-Sahhaf said two palaces were attacked: the Peace Palace, used for foreign dignitaries, and the Azzouhour Palace, a museum once used by the royal family, which was overthrown in 1958. Pointing to the damaged Peace Palace, al-Sahhaf lashed out at Rumsfeld.

"This criminal dog calls it a military site," the minister said.

Despite the apparent setbacks, Saddam's regime was taking a hard line -- denying military setbacks and verbally attacking its enemies in a show of public resolve.

Asked Friday night about an Iraqi counterattack, al-Sahhaf replied, "Our leadership and our armed forces will decide this, in what guarantees the defeat of those mercenaries, God willing." Speaking of Rumsfeld and President Bush, he declared, "Those only deserve to be hit with shoes."

During the day, Iraqi television showed footage of Saddam meeting with his son Qusai, the commander of the Republican Guard, and the defense minister, Gen. Sultan Hashim Ahmad, presenting a united front. The television said the meeting took place Friday.

The leadership's bravado stands in contrast with U.S. claims that Saddam's control was in danger of crumbling.

In Baghdad itself, bravado was scarce. Radio Baghdad was knocked off the air, and the streets were deserted after the missile attacks. By Saturday, the radio resumed broadcasts playing patriotic music.

It was a contrast with the patina of normalcy in Baghdad during the day Friday.

Before the air raid sirens started again, the Iraqi Air Force stood before a flag-waving crowd -- on a local soccer field. The Air Force played in one of two Baghdad soccer games, winning 1-0 against a team from the city of Najaf.

Highlights were shown on local television; it was likely the most action for the Air Force since the war began two days ago.

Many shops and cafes remained open Friday afternoon, secure in the safety of sunlight. Only the presence of armed Baath Party activists and jeeps mounted with heavy machine guns cruising the streets served notice of the ongoing war.

In Washington, a senior U.S. official -- speaking on condition of anonymity -- said Friday's bombardment might not be as intense as originally planned because surrender talks were continuing with senior Iraqi officials. The official said if the negotiations faltered in the coming hours, the bombing would go full-throttle.

Earlier, aboard the USS Kitty Hawk, scores of bombs were readied to fire and stored in racks in the ship's cavernous hanger bay. Ordnance crews worked steadily through the day attaching global positioning system and laser guidance kits to 500-pound, 1,000-pound and 2,000-pound bombs and moving the ordnance from the ship's 22 weapons magazine to holding bays.

Dozens of F-14 Tomcats and F/A-18 Hornet strike planes loaded with bombs roared off the Kitty Hawk's deck before nightfall Friday.

Al-Sahhaf acknowledged Friday that one of Saddam's homes was hit in an earlier U.S. bombardment, but said no one was hurt. The Iraqi News Agency said 37 people were injured in Thursday night's Baghdad raid.

Al-Sahhaf also denied any U.S.-led advance into Iraq and argued that TV images of Iraqis surrendering were fabricated. "Those are not Iraqi soldiers at all," he insisted.

And he suggested that any captured U.S. and British soldiers may not be treated as prisoners of war under the Geneva Conventions. Al-Sahhaf said Iraq was considering how to treat them.

"Those are mercenaries," he said. "Most probably they will be treated as mercenaries, hirelings and as war criminals. ... For sure, international law does not apply to those."

Later, however, a statement issued in Saddam's name on the official Iraqi News Agency said Iraq will follow the Geneva Conventions with respect to any captured soldiers despite the "grotesque crimes" committed by the Americans.