Screaming Irish nationalist protesters interrupted a gala performance of the Royal Ballet's "Sleeping Beauty" at the Metropolitan Opera House last night, yelling insults at Britain's Prince Charles as he sat in a box seat next to First Lady Nancy Reagan.

"You bloody murderer!" one yelled. "This man up there is responsible for all the murders!"

New York City police arrested four people and charged them with disorderly conduct, although they said one might also be charged with assault. They would release no names by intermission, and said the four -- two men and two women -- were being held in a room below the opera house.

Outside, 3,000 protesters chanted "British terrorists! British terrorists!" as police on horseback kept a close eye on the crowd. One sign said "Prince Charles -- Blood Lineage to Jack the Ripper." Another said "Royal Creep."

The four hecklers apparently each paid the $200 ticket price necessary for entry to the benefit performance celebrating the Royal Ballet's 50th anniversary. The first one jumped from his seat at 7:25 p.m. just after the prologue to the ballet began. "This is an insult to the American people!" he yelled. The crowd, wearing black ties and exotic designer gowns, hissed.

The second interruption came 10 minutes later as a young woman stood up and screamed "Free Ireland Now!" She was dragged out by ushers and security men and shortly thereafter, just before the end of the prologue, another man and a woman stood up and started yelling. They too were dragged off in a more elaborate scuffle, and some members of the audience said they saw blood on the man's head.

Charles, who was in New York to help celebrate the ballet's anniversary, had been plagued by Irish protests since he arrived for his 24-hour stay yesterday morning. New York Mayor Ed Koch, a politically astute man always aware of his constituents, had proclaimed "England out of Ireland" just before embarking on a yacht cruise up the Hudson River with the prince and the first lady. Protesters shouted and carried signs as the prince's 20-car motorcade escorted by 16 motorcycle police pulled away from the South Street Seaport Museum after lunch aboard the yacht Highlander. Earlier, when the yacht was returning to dock, a high-speed boat and a rowboat flying Irish flags tried to approach, but Marine police boats escorted them to Brooklyn. And even before the prince's arrival, a Queens man had applied for a temporary restraining order to prevent Charles from co-piloting his helicopter over New York. Charles, as it happened, sat in the co-pilot's seat, but didn't do any piloting.

The interruptions at the ballet never stopped the performance, although there was furious talk at intermission that the prince might not return for the rest of it. But he did.

Naturally, the hecklers were the talk of the intermission.

"Wasn't that something," said British designer Mary McFadden. "I thought if they'd had shotguns they could have shot everyone in the audience." Police, however, said the hecklers had no firearms.

"I knew it the minute I saw her," said Joanne Winship, a ballet patron who was sitting next to one of the female hecklers. "I had a feeling; she didn't look like one of us."

But then, it would have been difficult to look like one of them. Thousands of New York socialites turned up in gowns that even they talked about.

"The costumes are unbelievable," said Joan Sovern, wife of Michael, the Columbia University president. "People don't usually dress like this in New York. Look at those feathers over there. Hilarious. I mean, the whole thing is drop dead."

Then Joan Sovern turned her head slightly. "And look at the little one in green," she said.

And then, New York being New York, the little one in green and the woman in feathers got up from their chairs, strolled over to each other and began talking excitedly. As it turned out, the feathers belonged to Rosalie Levine, wife of Joseph, the movie producer. The woman in green was Eugenia Sheppard, the syndicated fashion writer.

"Stavropolous," Levine said of her gown. He's a Greek designer who does Gov. Hugh Carey's wife's clothes."Oh, he was my designer before anybody ever heard of her," said Levine, meaning Evangeline Gouletas-Cary. "Please , don't put me in that category."

The evening began with a cocktail reception just prior to the performance. Prince Charles turned out to shake hands, and what a collection of New York's rich, social and political you could see. A sampling:

Happy Rockefeller, opera star Beverly Sills, cosmetic magnate Estee Lauder, CBS chairman of the board William S. Paley, socialite Marietta Tree, financier Felix Rohatyn, and World Bank President Robert McNamara, who arriver with Christina Ford, the former wife of the auto czar.

"Hot news," said Esther Coopersmith, the Washington Democratic fund-raiser.

"Oh, we've known each other for 20 years," said McNamara. "Old friends from Detroit."

McNamara and Coopersmith were part of the Washington contingent at the reception. Others among them were Reagan friend Robert Keith Gary, Jack and Bonita Wrather, Sen. Larry Pressler (R.-S.D.) and British Ambassador Sir Nicholas Henderson.

The prince certainly appeared to be in a good mood. He moved slowly up and down a narrow red carpet in a reception hall at Lincoln Center, shaking hands and having a pleasant word for everyone. Rich and famous New Yorkers, often a blase lot when it comes to other rich and famous, were just slightly more subdued than a fanatic fan club.

"Delicious," Elizabeth Rohatyn, wife of Felix, said of the prince.

"Well, we have our royalty," said Felix Rohatyn. "Ed Koch, Meade Esposito . . .

"I just finished a biography of you," said Christina Malkemus, a lawyer from Boston, to Charles. "Your accomplishments are remarkable."

"It's all rubbish," laughed the prince.

"I'm going to send you Aramis," Estee Lauder said to him.

"For me?" Charles responded.

"Very nice skin," Lauder said in an aside as he moved on.

After the performance, there was a dinner dance in a huge tent put up in Damrosch Park. Lester Lanin's Orchestra played a Welsh jig as the prince and Nancy Reagan arrived, side by side. They ate at the head table and were absorbed in their own conversation.

After the dessert of blueberries, raspberries and strawberries, the prince and Nancy Reagan had one dance on the parquet floor. Then he told her good night and, the first lady departed, he turned his attention to the younger women. First he danced with a friend from England and then a second young woman actually went up and asked him to dance.

He obliged, first to "Bad, Bad Leroy Brown" and then "YMCA" -- authentic disco. The prince wasn't bad.

Then he left, and to finish off the evening in a grand way, Elizabeth Taylor arrived. It was close to 1 a.m. but she was straight from her show "The Little Foxes" and sitting regally at her table, rubies clustered around her throat. She had spoken to both the prince and Nancy Reagan on their way out. "He reminded me of the last time we saw each other," she said. "It was in the south of France."