Thousands of people, many waving flags and wearing T-shirts with slogans backing Operation Desert Storm, rallied on the Ellipse yesterday with songs, prayers and speeches in support of American troops.

The U.S. Park Police estimated the number of marchers at 3,500. Organizers put the number at 5,000.

From the Lincoln Memorial, the marchers moved along 17th Street to Pennsylvania Avenue and the White House, where some traded barbs with anti-war demonstrators. Some of the marchers burned an Iraqi flag.

The march was led by motorcycle riders, many of them veterans decked out in sleeveless denim vests and yellow bows.

"We want to send a message to the troops, the American public and to Saddam Hussein that we are not going to bad-mouth our troops," said Sam Duncan, a veteran from Fairfax who rode with the bikers. "We want them to know . . . we support our troops and we are not going to belittle or forget them."

Speaking at the rally was Rep. Robert K. Dornan (R-Calif.), who was greeted with chants of "B-1 Bob." Dornan introduced 8-year-old Jeremy Roman, whom he said he had met minutes before in the crowd.

"Saddam Hussein stinks. We want victory!" the flag-waving child yelled as Dornan held him up to the microphone.

Dornan lashed out at the "motley group . . . of America-hating, Ho-Ho-Ho Chi Minh chanting people" who protest against the war. "Saddam Hussein is holding on, popping tranquilizers, hanging on like Adolf Hitler in his bunker . . . because he misreads the demonstrations in the streets," he said.

Adrian Cronauer, the former disc jockey whose experience in Vietnam was portrayed in the film "Good Morning Vietnam," drew applause with his greeting of "Gooooood Morning Americans!" Cronauer characterized the Iraqi president as a "merciless madman . . . who will not listen to reason . . . {or} world opinion and will not abide by moral principles or even common decency."

A group of veterans hugged and waved flags as Lee Greenwood's "I'm Proud to be an American" played.

"If we didn't support them when they come home, it would be as bad as dealing with the enemy on the battlefield," said Thomas Nowlin, 42, a Vietnam vet. "We didn't get the support, but we want to make sure these troops get it."