KABUL, Afghanistan - The United Nations has called for Afghan human rights investigators to be allowed into Bagram, the main U.S. base in Afghanistan, after reports that poorly trained U.S. soldiers there had repeatedly abused prisoners.

Richard Provencher, U.N. spokesman in Afghanistan, said yesterday that abusers should be punished and that investigators from the Afghan Independent Human Rights Commission should have access to detainees and be allowed to monitor their cases.

Afghan President Hamid Karzai, on the eve of his meeting today with President Bush in Washington, said he was angry about the reported abuse and called for more Afghan control over the operations of the 16,700 U.S. troops in his country as well as punishment for any U.S. soldiers who mistreat prisoners.

Also yesterday, the U.S. military said that U.S. airstrikes and ground troops killed 12 insurgents who had attacked a coalition patrol in eastern Afghanistan's border region in the latest wave of fighting with Taliban-led rebels.

Saturday's fighting in eastern Paktika province left one U.S. soldier slightly wounded. Spokesman Lt. Col. Jerry O'Hara said rebels had sneaked across the border from Pakistan and had opened fire on American and Afghan forces.

The latest violence came as Karzai prepared to meet Bush in Washington, where the two leaders are expected to discuss the prisoner abuse allegations among other topics.

The New York Times detailed yesterday fresh allegations of mistreatment of prisoners by U.S. forces, noting the Army's criminal investigation into the deaths of two Afghans at the Bagram base north of the capital Kabul in December 2002.

In Texas, Spc. Brian E. Commack was sentenced in a court-martial on Friday to three months in prison after pleading guilty to the 2002 attack on prisoner Mullah Habibullah in Afghanistan. Cammack, of the Army Reserve's 377th Military Police Company in Cincinnati, said he was angry when he struck the prisoner twice in the thigh with his knee. The prisoner had allegedly spit on his chest.

In a plea bargain, Army prosecutors agreed not to pursue a charge of maltreatment against Cammack, who agreed to testify in other cases related to the deaths of two inmates at Bagram. He will be demoted to private, fined more than $3,200 and given a bad-conduct discharge.

Karzai - often viewed by critics as an American puppet - insisted that abusers be punished.

"This is simply not acceptable," he told CNN yesterday. "We are angry about this. We want justice. We want the people responsible for this sort of brutal behavior punished and tried and made public."

The U.S. military has said it would not tolerate any abuse. The White House said Friday that Bush was "alarmed" by the reports of abuse and wants them investigated thoroughly.

Karzai also called for an end to U.S. raids on Afghans' homes unless the government is notified beforehand. The Defense Ministry said all arrests should be made by Afghan authorities.

Provencher, the U.N. spokesman, said all Afghan detainees should be treated in accordance with international law and called for "firm guarantees" that there would be no more maltreatment.

Karzai also rejected criticism of his efforts against opium poppy growers, saying yesterday that the government had worked hard to eradicate poppy fields. He blamed Western countries for a lack of support.

The criticism came in a State Department memorandum reported in the Times yesterday. The memo attributed the lagging poppy eradication effort to a reluctance on the part of Karzai and others in the Kabul government to take on powerful warlords in Kandahar Province and elsewhere.

But Karzai said the criticism was part of an effort to shift blame from the United States, Britain and others that have failed to deliver economic aid.

"We are going to have probably all over the country at least 30 percent poppies reduced," Karzai said in an interview with CNN. "So we have done our job. The Afghan people have done their job. Now the international community must come and provide alternative livelihood to the Afghan people, which they have not done so far."

"Let us stop this blame game," he added.

The Associated Press and New York Times News Service contributed to this article.