JERUSALEM -- The killing of Yitzhak Rabin may have emerged from a plot involving several people, Israeli authorities investigating the assassination said yesterday as more people were arrested.
Police revealed the arrest of the head of a right-wing Jewish extremist group, and Israel Radio reported that another man is being held for questioning in the death of the prime minister Saturday.
Two brothers, Yigal and Hagai Amir, already are accused in the assassination.
Charges against a wider group would fuel recriminations in Israel that the assassination was nurtured by the rhetoric of opponents of the government.
Police yesterday brought Avishai Raviv, the head of the right-wing Eyal organization, to a Tel Aviv court, alleging he was a "catalyst in the murder."
He was ordered held for seven days.
Police refused to confirm the Israel Radio report that a fourth man was being questioned.
Under Israeli law, suspects can be interrogated secretly for 48 hours without a lawyer before being brought to court.
In other repercussions of the assassination:
* The top official in charge of Mr. Rabin's protection resigned, and three other secret police officers were suspended after an initial report found their security arrangements lax.
* The government ordered a state commission to investigate security breaches that enabled the assassination to be carried out.
* Interim Prime Minister Shimon Peres told his Cabinet the government must crack down on extremists who incite violence.
* Mr. Peres has decided to try to serve out the remaining year of the Mr. Rabin's term rather than call early elections, according to top Labor Party officials.
The arrest of Mr. Raviv indicated a wider net is being cast by the Israeli secret police, which is investigating associates of the Amir brothers.
Yigal Amir, 25, has admitted shooting Mr. Rabin as the prime minister left a peace rally.
His brother, Hagai, 27, is charged with preparing the lethal hollow-nose "dum-dum" bullets Yigal Amir used.
Police said yesterday that Mr. Raviv, who attends the same university as Yigal Amir, is "suspected of conspiracy to commit a felony, and not preventing a felony."
They gave the judge secret evidence in a sealed envelope.
"This is a political investigation. This is a dictatorship," shouted Mr. Raviv, 28, as he was brought to court.
He told the judge he was counter-demonstrating at the peace rally when Mr. Rabin was killed. But he denied knowing of Yigal Amir's act.
Mr. Raviv is a philosophy student at Bar-Ilan University near Tel Aviv, where Yigal Amir studies law.
He said Yigal Amir had made unspecified threats, but "nobody took him seriously. Words are one thing and actions are another."
"This was talk, but this was idle talk," he told Judge Edna Beckenstein.
He said Yigal Amir was familiar to members of Eyal, but was not a member. Eyal is an acronym for the Fighting Jewish Organization, thought to consist of about a dozen militant activists.
"Eyal is a legal movement," Mr. Raviv told the court. "All the security officials know the movement is legal and no one has ever proven anything against us."
Yigal Amir, a third-year law student at Bar-Ilan, has said he was justified in killing Mr. Rabin because he felt the prime minister was betraying Israel's biblical right to the land he has agreed to place under Palestinian authority under the peace agreement with the Palestinians.
The shake-up of the Israel secret police unit in charge of protection came after a preliminary report that said because of "planning and security deficiencies the murderer succeeded in approaching the Prime Minister within a lethal distance."
None of the secret police officials was named. Israeli publications are not permitted to name members of the organization, called the Shin Bet.
The orders for a crackdown on extremists came from Mr. Peres at a Cabinet meeting. Cabinet Secretary Shmuel Hollander said "the government will protect the freedom of speech but at the same time is determined to prevent forcefully and with all means at its disposal the freedom to murder and incite to murder."
But Motti Kirschenbaum, head of the Israel Broadcast Authority, said he received a directive from the Israel attorney general not to broadcast "words of incitement."
The order brought a protest from the association of Israeli journalists.
The decision not to call for early elections will be announced after the seven-day official mourning period for the slain prime minister, according to Eli Dayan, deputy foreign minister and a Labor Party leader.
Mr. Peres, as interim prime minister, is expected to form a new coalition government to serve until the scheduled elections, Oct. 29. He rejected the idea of holding earlier elections, hoping instead to continue the peace process and win public support, Mr. Dayan said.
"We want to use the time to implement the agreement with the Palestinians" and to try to achieve a peace agreement with Syria, he said.
"I think in a year, we can reach these goals," he said. "We believe we will win the next election."
Amir family letter
Following is the text of a letter that the family of Yigal Amir, the confessed killer of Prime Minister Yitzhak Rabin, sent to Mr. Rabin's wife, Leah, and posted outside its home yesterday:
To the Rabin family,
A great tragedy has befallen us and the entire people of Israel with our son's murder of Prime Minister Yitzhak Rabin (of blessed memory).
The loathsome murder caused the people of Israel and us a terrible tragedy that shook to its foundations the education and values we have taught to our children -- love for the Jewish people, respect for one's fellow man, love for the country and for Jewish values.
Deeply ashamed, mourning and with bowed head, we ask for forgiveness and absolution from Mrs. Rabin, from the (Rabin) family and from all the people of Israel, and hereby declare our rejection of all acts of violence!!!
Once again, we ask for forgiveness and absolution.
The Amir family
Parents, brothers and sisters.