BAGHDAD, Iraq — Iraq’s prime minister says Saddam Hussein’s execution would help undermine the insurgency as the ex-president’s genocide trial heard more testimony yesterday of poison gas attacks on Kurdish villages two decades ago.

Prime Minister al-Maliki said he hoped the trial, which began in August, would not last long and “shortly a death sentence will be passed against this criminal tyrant, his aides and the criminals who worked with him.”

“Definitely, with his execution, those betting on returning to power under the banner of Saddam and the Baath [Party] will lose,” Mr. Maliki told reporters Wednesday in Najaf.

Saddam and six co-defendants are on trial for their roles in “Operation Anfal,” a military offensive against the Kurds in 1987–88. The prosecution says some 180,000 Kurds were killed and hundreds of villages destroyed.

Saddam and another defendant are charged with genocide, but all could face the death penalty if convicted.

Saddam also is awaiting a verdict in a first trial in connection with the deaths of about 148 Shiite villagers in Dujail after an assassination attempt against him in 1982.That verdict is expected next month, and if convicted, Saddam could also face death by hanging.

Both trials are being closely watched by the American-backed Iraqi government, which is battling an insurgency in which Saddam’s supporters play a major role.

Saddam’s supporters have long maintained that the trials are unfair and that the Shiite-dominated government has interfered in the judicial process — charges that Iraq’s new leaders have denied.

During yesterday’s session, two witnesses testified that villagers fled in panic after a chemical weapons attack on northern Iraq in 1988, with some taking refuge in the mountains where Iraqi air force planes bombed them.

“People in my village were screaming that they were contaminated by chemical weapons,” witness Abdullah Saeed, a 79-year-old Kurd, testified.

“We loaded children, women and other persons infected with chemical weapons onto three trucks and fled to another village,” Mr. Saeed said, recalling the day in April 1988 when Saddam’s forces bombed two neighboring villages, causing clouds of smoke to drift toward his home. A second witness from the same village of Jalmard told the court that as he and other villagers fled the chemical cloud into the mountains, Iraqi air force planes bombed them.

“My nephew and another man got killed, and we left their bodies lying in the mountains,” testified Bakir Qader Mohammad, 72.

Mr. Saeed said that, as the people left their village in a convoy of trucks, Saddam’s forces stopped them and took them to a detention facility, where sanitary conditions were appalling.

Witness Mohammed said the camp where they were ultimately detained in southern Iraq, Nugrat Salman, was so bad that hundreds of people died of malnutrition and diseases like cholera.

Mr. Saeed testified that at least 1,800 of the 7,000 prisoners in Nugrat Salman died of malnutrition.

When the presiding judge questioned his casualty figure, Mr. Saeed said: “Before we were released from detention, one of the prisoners managed to steal a prison document, which showed that number.”

Mr. Saeed that after water was cut in the detention camp, a group of prisoners approached a prison warden called Hajjaj — whom earlier witnesses have accused of abusing detainees.

“We went to beg Hajjaj to give us water, but he told us: ‘we cut the water so that you’d die, you came here to die.'”

The court then adjourned until October 30. On Wednesday, two other Kurds told the court how they survived massacres conducted after guards took them in trucks into the desert, telling them they were being moved to another detention center.