An Iraqi Kurd described a chemical weapons attack on his village nearly two decades ago during Tuesday's session of the trial of Saddam Hussein.
The witness said jets dropped poison gas that blinded villagers and caused them to vomit.
Saddam is charged with genocide during Operation Anfal, a military campaign in 1987 and 1988 that prosecutors say wiped out dozens of villages and killed 180,000 Kurds. This is the ousted Iraqi leader's second trial for crimes against humanity.
Two of Saddam's six co-defendants also took the stand Tuesday, insisting that Iraqi forces were only attacking Iranian troops and Kurdish rebels during the campaign.
One of the defendants is Saddam's cousin Ali Hassan al-Majid, known as "Chemical Ali" for his role in gassing civilians.
On Monday, the ousted Iraqi leader refused to enter a plea or state his name before the judge. The judge then entered a plea of not guilty on his behalf.
Saddam is still waiting for the verdict from his first trial on charges of ordering the deaths of about 150 Shi'ite villagers after a 1982 assassination attempt. If convicted, he could face execution. That verdict is expected on October 16.
Some information for this report was provided by AFP, AP and Reuters.