Turkish terrorist Mehmet Ali Agca admitted today that he attempted to kill Pope John Paul II, but said he rejected the jurisdiction of the Italian court and declared his trial "over" moments after it began.

In a statement made to police shortly after his arrest that was read at the opening session of the trial Agca, 23, admitted he shot at the 61-year-old pontiff.

Agca's admission, however, did not constitute a formal plea of guilty, which is not necessary under Italian judicial practice. His statements on the witness stand were entered into the court record for consideration by the judge and jury.

If convicted, Agca, who was serving a murder sentence in Turkey when he escaped from prison in November 1979, would face a mandatory life sentence.

"Agca said that if he were not turned over to the Vatican -- where the attempt on the pope's life took place -- or to an international court within five months, he would begin a hunger strike."

The courtroom hearing, held in Rome's judicial city two miles from St. Peter's Square, is expected to last only three or four days.

The tall, dark-hared extremist, who since his arrest nine weeks ago has grown a heavy beard, was brought handcuffed into a courtroom crowded with Italian and foreign journalists and seated behind a special three-walled partition of steel and bulletproof glass.

Nearly obscured by the five khaki-clad carabinieri who stood in a semicircle around him, Agca sat impassively as his court-appointed lawyer, Pietro d'Ovidio, and the prosecutor argued over procedures for the trial of a foreigner and Italian jurisdiction over criminal acts committed on Vatican soil.

Then, after the court, composed of 10 jurors and two magistrates, withdrew to consider the procedural issues, Agca exploded in rage, obviously under the mistaken impression that the trial was already over. He yelled in Turkish, "What kind of justice is this in which the defense lawyer speaks before the accused, in which the court withdraws without listening to the defendant speak? I am speaking to the entire world," he said, adding that "there is torture in Italian prisons."

The misunderstanding may have been caused by linguistic problems. Although two interpreters were present, they had summed up the lengthy procedural questions for him in one sentence.And Agca's lawyer admitted that in their three meetings, he had used an English rather than a Turkish-speaking interpreter because he thought Agca, who reportedly speaks little English, would feel intimidated about speaking freely in front of a fellow Turk.

Although police have said they believe Agca may have received help in planning his assassination attempt, no new evidence that could point to an international plot has been produced.

Six eyewitnesses who identified Agca as the man who shot the pope denied seeing a second gunman.

Two American women who were wounded during the shooting did not return to Rome for the trial, but their testimony, in which they each said they had seen nothing, was read by magistrate Severino Santiapichi.

Also absent from the courtroom was the pope, who forgave his assailant from his hospital bed May 17. First released from the hospital June 3, the pope was readmitted June 20 and has been hospitalized for the past month for cytomegalo-virus, an infection related to the herpes family often caused by blood transfusions.

In the courtroom, the stony-faced but healthy-looking Agca compared Rome's model Rebibbia Prison to "a medieval jail" and said he has spent the past 60 days in an "inhuman situation," subjected to "pressure and threatened with death."

Agca said he would give the Italian government five months to turn him over to a proper court. "The trial is over, thank you," he concluded, provoking hearty laughter from those assembled.

The two magistrates heading the court read statements made by Agca during several days of interrogation shortly after the shooting, in which he recounted often conflicting tales of his travels through eastern and western Europe following his escape from prison.

The prosecution pleads its case Tuesday and the defense is expected to make its case Wednesday.