Two former aides to Saddam Hussein have refused to testify against the ousted Iraqi leader at his trial in Baghdad.
Both witnesses said they were in court under duress
Former head of the presidential office Ahmed Khudayir and ex-intelligence chief Hassan al-Obeidi both said they had been brought against their will.
During another stormy session, Saddam Hussein said he too was forced to attend and shouted "Down with Bush".
The ex-leader and seven former aides are being tried in connection with the killing of 148 Shia villagers in 1982.
The defendants deny all the charges.
Mr Khudayir and Mr Obeidi are the first aides to Saddam Hussein to testify at the trial.
'Unfit to testify'
The BBC's Jon Brain in Baghdad says the prosecution had been hoping they would confirm that the former president had ordered the massacre of the village of Dujail.
Mr Khudayir headed Saddam Hussein's presidential office from 1995 to the fall of the regime. He attended a military planning session on 9 April 2003, two days before the Americans entered Baghdad.
But he told the court he knew nothing of the events at Dujail in 1982.
When shown a document, purported to contain his signature, which apparently showed Saddam Hussein had ratified "the execution of the Dujail detainees", Mr Khudayir said: "I don't remember anything at all."
He added: "I am not fit to be a witness in this case."
Mr Obeidi said he had been absent during the events at the centre of the trial. Saddam Hussein laughed as he spoke.
Both men said they had been brought before the court under duress.
At the start of Monday's three-hour session, Saddam Hussein continued a stormy exchange with the new chief judge, Raouf Abdul Rahman, who accuses of being biased.
The defendants had vowed not to appear in court until the return of their lawyers - who are calling for the removal of Judge Rahman and boycotting the proceedings.
Judge Rahman ordered the defendants to return to court
The chief prosecutor had asked the chief judge to bring Saddam Hussein and his co-defendants to court by force if necessary.
On entering court, Saddam Hussein said: "They have forcibly brought me here."
He told the judge: "Exercise your right to try me in absentia. Are you trying to overcome your own smallness?"
"The law will be implemented," said the judge, who banged his gavel on several occasions.
The former leader wore a blue traditional Arab robe and a black jacket in contrast to the suit he had worn previously.
"Down with the traitor, down with Bush. Long live the ummah [Islamic nation]," Saddam Hussein shouted.
His half-brother Barzan Ibrahim al-Tikriti scuffled with guards as he was brought in.
Saddam Hussein attended court in traditional Arab dress
Both then continued to harangue the judge throughout the early proceedings, refusing orders to sit down and be quiet.
"This is not a court, this is a game," Saddam Hussein shouted.
Barzan Ibrahim sat on the floor with his back to the judge. The case has now been adjourned until Tuesday.
The new chief judge took over last month after the resignation of his predecessor Rizgar Amin and has adopted a more hardline approach to the defendants.
Saddam Hussein and some of his co-defendants failed to show up at the past few sessions.
Our correspondent says the prosecution was aware that the spectacle of an empty dock risked further undermining a trial that has repeatedly descended into farce.