The allied ground offensive, blessed with "tremendous success" for a second day, rolled over Iraq's troops and units of its vaunted Republican Guard with little difficulty, the military said Monday.

"We are meeting the enemy and beating the enemy," Marine Brig. Gen. Richard Neal told a late-afternoon briefing. Iraqi prisoners numbered near 20,000, a forward U.S. post had been carved out 50 miles into Iraq, and allied troops advanced on Kuwait City."Terrorism remains the only Iraqi success to date," Neal said, pointing to what he said was an accelerating number of oil field fires and civilian atrocities attributed to the Iraqis.

In the second day of the ground war, Neal put American casualties at four dead, 21 wounded. Lt. Gen. Khalid bin Sultan, joint Arab forces commander, said five of his forces had been killed and 20 had been wounded in action.

The allies "continue to achieve tremendous success against the Iraqi forces," and face "light to moderate resistance," Neal said.

In what he called an "extremely conservative" accounting of Iraqi losses, Neal said the allies had destroyed more than 270 tanks since the ground offensive began. Among them, he said, were 32 Soviet-made T-72s - the Iraqis' most advanced tanks and the tank used by the highly touted Republican Guard.

Neal said allied troops had engaged some units of the Republican Guard and "They're being beaten."

But at a base in Saudi Arabia, F-15 squadron commander Lt. Col Steve Turner said 80 Guard tanks had been spotted on the move toward the allied forces. "They're finally flushing," he said. "They've got to do something - either that, or get killed in their holes."

Neal said the allied advance was so quick and so successful that army reserve units originally slated to be held back for the first 24 hours were sent in just 12 hours into the offensive.

One of the allies' biggest problems was coping with the thousands of Iraqis who were surrendering.

Neal said 18,000 Iraqis had surrendered to allied forces; Khalid put the total prisoners at 20,000.

The officials would not say where the Iraqis were captured, but the bulk appeared to have belonged to front-line units that had not been expected to put up as much of a fight as Saddam Hussein's better-equipped second-tier forces.

In one poignant moment, a wounded Iraqi POW, unable to walk without help, kissed one of the Saudi captors supporting him. The scene - in Kuwait - was filmed by British journalists operating outside the Pentagon's "pool" system.

In what officers called the largest helicopter operation in military history, more than 2,000 men of the Army's 101st Airborne Division were airlifted more than 50 miles into Iraq on Sunday (see story on A2).

The airborne operation was part of a push to establish a strong toehold in Iraqi territory west of Kuwait - in order to cut supply lines to Iraqi forces in Kuwait and possibly move to encircle them.

Out in the Persian Gulf, Marines in an amphibious task remained aboard ship during the offensive's first day. Once night fell, helicopters from the force roared toward the Kuwaiti coastline in a dual mission: reconnaissance - and keeping Iraq guessing about whether a beach assault was imminent.

In the first such known attack of the war, Iraq launched a Silkworm anti-ship missile at allied warships off Kuwait Monday, British officials said, adding that it was intercepted by a Sea Dart missile fired by the British destroyer HMS Gloucester.

One U.S. officer said missile batteries on Faylakah island, at the entrance to Kuwait Bay, were targeted Monday with fire from the 16-inch guns of a U.S. battleship and bombed by warplanes including U.S. B-52s.

In Baghdad, overnight bombardment sent clouds of black smoke billowing over the city's western edge, Associated Press correspondent Salah Nasrawi reported Monday. Guests of the al-Rashid Hotel, where most Western journalists are based, reported enormous explosions in downtown Baghdad.

The air war did not pause. Neal said more than 3,000 missions were flown in the past 24 hours, including 1,300 over Kuwait and southern Iraq and 700 in support of the ground forces. Four U.S. aircraft were lost, but three of the five airmen were rescued.

In his first public appearance since the first night of ground fighting - at a White House ceremony marking Black History Month, President Bush said the ground war was "on course and on schedule."

"We will prevail. Kuwait will soon be free," he said. But he cautioned against euphoria. "There are battles yet to come and casualties to be borne."

Khalid, the Arab military commander, said at a Riyadh briefing this morning that despite the losses they are taking, the Iraqis are good soldiers. Their handicap: "They don't believe in what they are fighting right now."

Reports on battle action were sketchy, because the Desert Storm command was issuing only limited information, and dispatches from reporters in military-organized news pools at the front were slow in reaching rear areas.

But the picture that emerged was of a fast-moving ground war that brought units of the U.S. Marine's 1st and 2nd Divisions - as well as the Army's 82nd Airborne - to the outskirts of Kuwait City.

Jenkins, the commander of the Marine landing force, said most of the Marines, moving in two lines, had advanced past barriers the Iraqis had set up as artillery "kill zones."

The fast break over land to the Kuwaiti capital followed several days of heavy artillery and air attacks as well as minefield-clearing operations. It was augmented, according to allied sources, by a parachute drop outside the city by elements of the Army's 82nd Airborne Division.

Also punching northward into Kuwait on the ground were allied Arab forces including Kuwaiti, Egyptian, Syrian and Saudi troops.

Those troops moved within 40 miles of Kuwait City Monday, and expected to link up with other allied troops there on Tuesday, according to AP special correspondent Mort Rosenblum, who was with the Arab forces. He said they encountered only sporadic artillery fire.

At separate points along a 300-mile front, French and British forces also joined in the offensive.

Details also emerged about the role of the Egyptian forces. A military source said Egyptian gunners had fired more than 1,200 tons of ammunition on Iraqi positions in the first 24 hours of the offensive, and helped with allied mine-clearing efforts.

Smoke pouring from blazing Kuwaiti oil fields hampered allied bombing missions but did not slow troops on the ground, according to field reports.

If the smokescreen was meant to be an ally of Iraqi forces, it was a fickle one. Soon after the allied offensive began, the wind changed, blowing away the heavy clouds over one section - revealing nearly 100 camouflaged Iraqi artillery pieces that were quickly prey for allied warplanes.

The U.S. military command in Saudi Arabia said Monday the Iraqis had launched three Scud-type missiles overnight, one at Saudi Arabia and two at Israel. Israeli authorities reported no damage or injuries.