Attorneys representing Saddam and seven co-accused on charges of crimes against humanity considered a second day of hearings set for November 28 to be "cancelled and illegitimate", lead counsel Khalil al-Dulaimi told Reuters.

Interviewed in the Sunni Arab rebel stronghold of Ramadi, west of Baghdad, he said he felt personally threatened and renewed demands for the United Nations to intervene to stop the trial following Tuesday's killing of lawyer Adil al-Zubeidi.

"We're facing daily threats and these threats prevent us from going to our offices and the court and from interviewing the witnesses," Dulaimi said.

"We call on the international community, the U.N. Security Council, the United States and all those involved to work on scrapping the criminal court as illegitimate, and also to pressure it to release President Saddam Hussein and his legitimate leadership team.

"The defence committee has decided to consider the November 28 date cancelled and illegitimate."

Coming less than three weeks after the killing of another lawyer for one of Saddam's co-accused, Tuesday's attack renewed international concerns about whether the trial can be held in Iraq given the sectarian violence still plaguing the country.

It was unclear what effect a defence boycott would have on the tribunal, which has the power to appoint counsel. However it would clearly dent efforts by the Iraqi and U.S. governments to show that the trial is entirely fair.

The defence team has said it is simply not safe to take part in the trial.

Zubeidi, who was defending Saddam's half-brother Barzan al- Tikrit and former vice president Taha Yassin Ramadan, was buried on Wednesday, virtually in secret. Police said close relatives interred him with a minimum of ceremony in the Shi'ite holy city of Kerbala, south of Baghdad, in line with Shi'ite custom.

Gunmen shot Zubeidi in his car in Baghdad; Thamer Hamoud al -Khuzaie, a fellow member of the defence team is in hospital with bullet wounds and head injuries sustained when the car crashed, a medical source said.

RULE OF LAW

U.N. Secretary-General Kofi Annan said the attacks undermined efforts to uphold the rule of law.

"It is vitally important that the security of all involved with the tribunal should be equally assured to ensure a trial free from intimidation and coercion," Annan said through his spokeswoman, Marie Okabe.

The anger dividing Iraq pervades the proceedings, but ministers refused to consider a move abroad after the murder of lawyer Saadoun al-Janabi the day after the trial opened on October 19. Tribunal and government officials made no comment.

President Jalal Talabani urged the government to ensure the safety of those involved in the trial.

The start of the trial was watched on television by millions of Iraqis -- both Zubeidi and Janabi spoke heatedly -- but some of Saddam's fellow Sunni Arabs called it "victors' justice" orchestrated by the Shi'ite- and Kurdish-led government.

The government has denied involvement in the murder of Janabi, who was kidnapped and killed the day after the trial opened by men who witnesses said identified themselves as employees of the Interior Ministry.

In the latest burst of violence, a suicide car bomb in the mixed Shi'ite and Sunni Arab town of Baquba, north of Baghdad, killed seven Iraqi policemen, army and medical sources said.

With five weeks until December 15 elections that Washington hopes will steer Iraq further along the path to stability and democracy, the Arab League stepped up efforts to organise a national reconciliation conference in Cairo.

An Arab League delegation has been visiting Baghdad to persuade politicians to attend the conference, which had originally been planned for November 15.

Billed as a way to heal deep sectarian rifts in post-Saddam Iraq, the conference was put off while organisers tried to lure more people to the table.

Senior Arab League official Ahmed ben Hilli said there would now be a meeting in the Egyptian capital on November 19 to prepare the ground for a main conference to be held some time later.

In western Iraq, where U.S. and Iraqi forces have been conducting an offensive since Saturday to clear the small frontier town of Qusayba of al Qaeda militants, the U.S. military declared the main phase of the operation complete.

(Additional reporting by Faris al-Mehdawi in Baquba, Alastair Macdonald, Paul Tait, Waleed Ibrahim, Aseel Kami, Lutfi Abu Oun and Ahmed Rashid in Baghdad, Irwin Arieff at the United Nations)