BAGHDAD, Iraq – Iraqi police arrested eight Sunni Arabs for allegedly plotting to kill the judge who prepared the indictment of Saddam Hussein, authorities said Sunday, the day before the ousted leader’s trial for crimes against humanity resumes.

A former U.S. attorney general, Ramsey Clark, arrived in Baghdad to help the defense but might not be allowed in court today when the first of up to 35 prosecution witnesses take the stand.

Tight security surrounds the proceedings, which are restarting after a five-week recess in a specially built courtroom in the heavily guarded Green Zone. The precise starting time was not announced due to fear of attack by both Saddam’s supporters and opponents.

The eight alleged plotters from Iraq’s Sunni Arab minority were apprehended Saturday in the northern city of Kirkuk, police Colonel Anwar Qadir said. He said they were carrying written instructions from a former top Saddam deputy, Izzat Ibrahim al-Douri, ordering them to kill investigating judge Raed Juhi, who prepared the case against Saddam and forwarded it to the trial court in July.

Mr. al-Douri is the highest ranking member of the Saddam regime still at large and is believed to be at least the symbolic leader of Saddam loyalists fighting American forces and Iraq’s new government.

“As an Iraqi citizen and a judge, I am vulnerable to assassination attempts,” Mr. Juhi told the Associated Press. “If I thought about this danger, then I would not be able to perform my job … I will practice my profession in a way that serves my country and satisfies my conscience.”

Saddam and seven co-defendants are charged in the killing of more than 140 Shiite Muslims after an assassination attempt against the former president in the Shiite town of Dujail in 1982. Convictions could bring a sentence of death by hanging.

Insecurity from the predominantly Sunni insurgency has complicated efforts to put Saddam on trial and forced draconian measures. For example, names of four of the five trial judges have been kept secret and some of the 35 witnesses may testify behind curtains to protect them from reprisal.

Defense lawyers had threatened to boycott the proceedings after two of their colleagues were slain in two attacks following the opening session Oct. 19. However, lawyer Khamees al-Ubaidi told the AP on Sunday that the defense team would attend after an agreement with American and Iraqi authorities on improving security for them.

On the eve of the hearing, Clark and former Qatari Justice Minister Najib al-Nueimi flew to the capital from Amman, Jordan, to lend weight to the defense team. Both have been advising Saddam’s lawyers and support their call to have the trial moved out of Iraq because of the violence.

However, neither Clark nor al-Nueimi has been officially recognized by the court as legal counsel. American and Iraqi officials said Saddam’s chief lawyer, Khalil al-Dulaimi, did not officially request permission for any foreign attorneys to attend the trial.