Saddam and six co-defendants stand accused of slaughtering 182,000 Kurds by gassing them and bombing their villages in the Kurdish regions of northern Iraq in 1987 and 1988.
The trial resumed after a three-week recess, on the day the United States marks the fifth anniversary of the September 11 attacks on New York and Washington that left close to 3,000 people dead.
On Friday a US senate report concluded that Saddam had no links with Al-Qaeda prior to the September 11 attacks, as US President George W. Bush's administration had repeatedly charged.
Saddam's presence in court may spark renewed debate over whether the United States was right to go to war on Iraq in March 2003, since when more than 2,600 US troops have been killed.
Witness tells of attack
A former female Kurdish guerrilla told the court how she witnessed first-hand the horror of gas attacks against her people in the late 1980s.
Katherine Elias Mikhail, once a peshmerga Kurdish guerrilla, described how she was present when first her unit and then a year later her village were gassed by Saddam's air force.
"I saw hundreds of people -- not dozens but hundreds -- and they werevomiting and teary-eyed," she said describing a 1987 attack on a peshmerga base.
"People with me collapsed because they had lost their sight." In late 1988, the planes struck her village.
"We had been frequently attacked by aircraft, but this time the sound ofthe explosions was not as loud as before and after the explosion there was white smoke," said the woman who now works as a writer in the United States.
Mikhail, who has long since shed her guerrilla fatigues for a business suit, said she lost most of her family to the old regime.
She said her complaint was against Saddam and Chemical Ali and "the international companies who supplied the Iraqi regimes with these weapons".
19 killed in latest violence
As the trial got underway a suicide bomber blew himself up inside a minibus full of Iraqi army recruits in Baghdad, killing 14 and wounding three.
Police said the bomber boarded the minibus outside an army recruiting centre in western Baghdad and detonated the bomb.
Recruitment centres for the Iraqi army and police, key elements of Washington's strategy for pulling out its own troops, have been frequent targets for insurgents from the Sunni Arab minority.
Meanwhile gunmen in two cars ambushed a bus carrying oil employees in northern Iraq, killing four and injuring another.
The bus had been taking the employees from Beiji, the country's biggest refinery, 250 kilometres north of Baghdad, to Tuz Khormato district about 120 kilometres southeast of Beiji.
Iraq's oil infrastructure is frequently targeted by insurgents who blow up pipelines and target oil workers in attacks.