A Yemeni man with suspected Al Qaeda links told a court that he killed three American missionaries to defend Islam, believing they were sterilizing Muslim women and trying to convert Muslims to Christianity.

Abed Abdul Razak Kamel, 30, said he moved from the capital of San'a to this city 125 miles south after he heard about missionaries working in Jibla at a Southern Baptist-run hospital.

"I acted out of a religious duty ... and in revenge from those who converted Muslims from their religion and made them unbelievers," the bearded Kamel said Sunday as his trial opened under tight security.

"They were also committing another corruption," he said, claiming he had learned that women were visiting the hospital to get sterilized.

"This is a violation of Islam," he told the court.

Kathleen A. Gariety of Wauwatosa, Wis., Martha C. Myers of Montgomery, Ala., and William E. Koehn of Kansas were killed in the Dec. 30 shooting. Donald W. Caswell, of Levelland, Texas, was wounded.

Prosecutor Ibrahim al-Delemi asked for the death penalty.

Kamel, who was arrested the day of the shooting, told the court he coordinated the attack with Ali al-Jarallah, another suspected Muslim extremist accused of gunning down a Yemeni leftist politician two days before the Jibla hospital attack.

Kamel said he had planned his attack for 18 months, and often consulted with al-Jarallah. He even scouted his target, visiting the hospital often and asking questions about its activities.

On the day of the shooting, he walked into the hospital with a semiautomatic rifle hidden under his clothes and opened fire on a staff meeting. He said he fired two shots at each target.

"We agreed. (Al-Jarallah) would kill seculars, and I would target Christians," Kamel said.

Kamel's next court appearance was set for April 30.

Al-Jarallah's trial opened Sunday in San'a, with a judge reading charges during the 15-minute session. It was to resume Wednesday.

Al-Jarallah, a member of Yemen's fundamentalist Islamic Reform Party, refused to answer any questions and called his trial "a farce, a legal scandal."

Yemeni security officials said they believe both suspects belong to a terrorist cell linked to Al Qaeda.

Audiotapes with the voice of Al Qaeda leader Usama bin Laden were found at Kamel's house. Officials have said they believed the cell was plotting attacks against at least eight targets, including foreigners and Yemeni politicians.

The Saudi-born bin Laden has family ties to Yemen and is believed to have strong support here.

In October 2000, an explosive-laden boat rammed into the USS Cole destroyer in the southern Yemeni port of Aden, killing 17 U.S. sailors. The attack was blamed on Al Qaeda, and ten key suspects escaped a prison April 11 and remain at large.

After the attack, funding problems forced the Virginia-based International Missions Board to transfer control of the hospital to a local charity founded by Yemeni Foreign Minister Abu Bakr al-Kerbi, a Canadian-trained doctor.

The hospital's chief is now a Yemeni Health Ministry official, and many foreign doctors, including Americans, still work there.

Residents have said the American victims never discussed religion. Yemeni law prohibits non-Muslims from proselytizing in this overwhelmingly Muslim country.