Standing near rows of white grave markers, Secretary of State Colin Powell (search) on Monday honored 5,000 Iraqi Kurds who died in a chemical weapons attack and pledged such brutality was gone along with Saddam Hussein (search).

With relatives of victims standing before him, Powell said: "I can't tell you that Saddam Hussein was a murderous tyrant -- you know that. What I can tell you is that what happened here in 1988 is never going to happen again."

Powell added that Saddam is "running and hiding. He's going to be running until we catch him or he dies."

After Powell dedicated a memorial and museum to commemorate the victims, women wearing black thrust bouquets of flowers toward him. Many in the audience wept, holding pictures of family members killed in Halabja (search).

The massacre on March 15, 1988, in this northeastern Iraqi city, seven miles from the Iranian border, has been cited repeatedly by President Bush as evidence of Saddam's brutality. Defense Secretary Donald H. Rumsfeld (search) visited the site of another mass grave this month, in Mahaweel, where lie bodies of an estimated 3,100 Shiite Muslims, killed as Saddam's forces smashed a rebellion after the 1991 Persian Gulf War (search).

Despite the public high-level attention, human rights activists contend that for all the focus on the atrocities, the American response to the mass graves has been slow, disorganized and inadequate. In particular, crucial evidence for any possible criminal trials already has been destroyed.

"It's rather shocking, in fact, the investment ... of very, very little into this area -- not only of the mass graves but everything the mass graves represent," said Joe Stork of Human Rights Watch.

Saddam's government killed an estimated 300,000 Iraqis, said Sandy Hodgkinson, the top human rights official in the U.S.-led civilian administration. As many as 500 mass graves are spread across Iraq, and coalition authorities have received formal reports of 151 sites, Hodgkinson said.

Much of the evidence has been destroyed, in part because of the anguished digging of relatives looking for bodies of family members at Mahaweel and other sites, human rights groups and coalition officials agree.

Most of the known mass grave sites have not been secured by coalition forces, either because of a lack of guards or out of respect for relatives' wishes, Hodgkinson said. The coalition is working with Iraqi groups to train guards for some sites, to begin issuing guidelines for forensic examinations and to train Iraqis in correct forensic work, she said.

Critics say it's already far too late, nearly five months after the fall of Baghdad.

"I haven't seen evidence of the level of resources and commitment and personnel that would be required to help the Iraqis do this properly," said Susannah Sirkin of Physicians for Human Rights.

Forensic teams from human rights groups or coalition countries have not been able to visit, either, Hodgkinson said, because security remains uncertain.

International tribunals handle prosecutions for atrocities in the former Yugoslavia and Rwanda. But here, the United States has insisted any trials be conducted by a new Iraqi legal system still being developed. Many human rights groups agree that Iraqis should lead the legal process, but say international participation is crucial for it to be legitimate and impartial.

"This is a judicial system that is just beginning to be built. It's not a judicial system that has had a lot of experience looking into this sort of crime," Sirkin said.

Coalition forces, human rights groups and Iraqi representatives are pleading with relatives of the missing not to dig up graves. But patience is stretched to the breaking point when relatives see no progress, said Sam Zia-Zarifi of Human Rights Watch. His organization had persuaded relatives in the southern city of Basra to leave a mass grave site alone, but when news spread of the Mahaweel digging, the relatives rushed to the Basra site and unearthed three dozen bodies.

The digging destroyed what could have been prime evidence of crimes against humanity, Zia-Zarifi said. Investigators had interviewed witnesses and found documents indicating the executions were ordered by "Chemical Ali" Hassan al-Majid, a former top Iraqi official captured by the United States last month, who also is suspected in the sarin gas attacks on Kurds.

In Halabja, Powell was joined at the memorial service by two Kurdish leaders who have fought in the past but now are renconciled: Jalal Talabani and Massoud Barzani. Powell said the two Kurdish leaders, whose regions were largely outside Baghdad's control before the war, told him they now are committed to a unified Iraq.

Talabani said Kurds since time immemorial have felt their only friends are the mountains -- clearly visible a few miles away. As some in the audience held up signs for Powell saying "Thank you," Talabani said the Kurds now believe they aren't friendless after all.