Zvonko Busic, center, is in custody of FBI agents on Sept. 13, 1976, after returning to the United States from Paris to face air piracy and murder charges in connection with the hijacking of a TWA Boeing 727 jet. (AP)

Zvonko Busic, a Croatian nationalist who served 32 years in prison in the United States for hijacking a plane and planting explosives that killed a policeman, has committed suicide. He was 67.

Police said Mr. Busic was found dead Sept. 1 at his home in Rovanjska, near the coastal Croatian town of Zadar. They said he left a suicide note.

Mr. Busic was working as a waiter in New York when he led a group of five people who on Sept. 10, 1976, hijacked TWA Flight 355 flying from New York to Chicago with about 80 passengers and crew members on board.

Mr. Busic and his cohorts, including his Oregon-born wife, the former Julienne Eden Schultz, said at the time they wanted to draw attention to Croatia’s bid for independence from communist-led Yugoslavia.

Soon after takeoff from New York’s La Guardia Airport, Mr. Busic got word to the pilot that he had planted bombs aboard the plane and another in a locker at New York’s Grand Central railway station. Officer Brian J. Murray was killed and three others were seriously injured as they tried to defuse the device from the locker, which they had taken to a demolition range in the Bronx.

The skyjackers said another bomb would go off “somewhere in the United States” unless a long statement about Croatian independence appeared in the New York Times, The Washington Post, the Los Angeles Times, the Chicago Tribune and the International Herald Tribune.

In his memoir, former Post executive editor Benjamin C. Bradlee wrote that in consulting with counterparts at the other newspapers, “none of us had any stomach for reading a headline in the next day’s paper that went something like this: ‘Hijackers kill 62 Americans after U.S. editors refuse to publish documents.’ ”

Bradlee said he asked the FBI to make a statement about the strong “public interest” in printing the screed. All the papers except the Herald Tribune complied, but their editors minimized the potential impact of publishing.

“Since nothing had been said about how many copies of the Post had to contain the story,” Bradlee wrote, “we didn’t have to include the story until the final minutes of the final edition.” They also used agate type, the tiny print used for box scores and classified advertisements.

The hijackers forced the pilots of the Boeing 727 to fly the plane to Montreal, then London and Paris. The plane was not meant for transatlantic travel, and it made several stops for refueling. At one stop in Gander, Newfoundland, the kidnappers released 35 hostages.

They eventually landed at Charles de Gaulle Airport outside Paris, where authorities slashed the jet’s tires. When the skyjackers confirmed that their statements had been printed by the newspapers, they surrendered.

In 1977, the Busics were convicted in federal court in Brooklyn on charges of air piracy. They also were also convicted on state charges of kidnapping and second-degree murder, the New York Times reported.

The Busics received life terms. The others involved — Frane Pesut, Petar Matanic and Mark Vlasic — received 30-year sentences.

“I did not do this act out of adventuristic or terroristic impulses,” Mr. Busic told the court before receiving his sentence. “It was simply the scream of a disenfranchised and persecuted man.”

“If I had ever imagined that anyone could have been hurt,” he added, “I would never, even if it had cost me anonymous death at Yugoslav hands, embarked on that flight.”

Zvonko Busic was born Jan. 23, 1946, in the impoverished village of Gorica. In 1969, he met his future wife in Vienna, where she was studying.

Mr. Busic escaped from a federal prison in upstate New York in April 1987 but was quickly recaptured. In 2008, Mr. Busic was paroled in the United States for good behavior and returned to Croatia. As a condition of his parole, Mr. Busic was barred from returning to the United States.

Three other conspirators were released in 1988, and Mr. Busic’s wife was released in 1989.

In Croatia, which gained independence after the Yugoslav wars of the 1990s, Mr. Busic received a warm welcome as a hero of the country’s struggle for statehood. The country joined the European Union in July.

— Staff and wire reports