Sudan has agreed to accept an expanded African Union force in its western Darfur region to help protect civilians against marauding pro-government militia. Sudan's foreign minister briefed the U.N. Security Council Thursday, shortly after a top U.N. official reported that the potential for genocide still exists in Darfur.

As he emerged from a closed-door Security Council meeting, Sudan's Foreign Minister Mustafa Osman Ismail told reporters the African Union would boost its presence in Darfur from the current 80 monitors to as many as 5,000 police officers. "I discussed it with the president of the AU commission just a few days ago, and they are going to bring more than 1,000 police together with monitors, in order to work with the Sudanese police forces for protection and checking. So that's going to happen," he said.

When a reporter noted that the AU is talking about 5,000 police officers, he responded by saying "they said they want 3,500, but we told them we want to go up to 4,000, and if they want to go to 5,000, no problem."

The Sudanese minister said the expanded force would have a stronger mandate than the current observers, but gave few details.

His comments came on a day when the Secretary General's top adviser on the prevention of genocide told the Security Council war crimes have probably taken place on a large and systematic scale in Darfur.

Special envoy Juan Mendez, just back from a visit to the region, told reporters afterward that his mission had not been to determine whether genocide had been committed. But Mr. Mendez, an Argentinian, said his tour of the region had convinced him that the potential for genocide still exists. "The vulnerability of certain ethnic groups in Darfur is such and the instability of the situation generally that we have not turned the corner on preventing genocide from happening in the future or even near future in Darfur," he said.

U.N. High Commissioner for Human Rights Louise Arbour, who accompanied Mr. Mendez on his mission, said Darfur residents live in what she called "a prison without walls," afraid to go out of their homes. She said an international police presence is desperately needed to monitor Sudanese police, some of whom are accused of working with the Janjaweed.

Washington's U.N. Ambassador John Danforth emerged from Thursday's Security Council meeting saying he had heard two conflicting versions of the Sudan story. One, he said, from the U.N. envoys, he called 'very bleak, along with an opposing view from Foreign Minister Ismael.

He said the Khartoum government had not shown that it was taking action to halt the pro-government Arab militias, or Janjaweed. "We have to make sure the government of Sudan is doing what it says it's doing," he said, "and as we say in my state [Missouri], 'They've got to show us.' This is a 'show me' situation."

Ambassador Danforth described as "baloney" a charge by Sudan's President Omar Hassan al-Bashir that the United States had helped train and arm rebels in Darfur. The Sudanese leader made the charge in an interview published Thursday in an Egyptian newspaper.

The United Nations says more than 1.6 million people have fled their homes in Darfur since early last year. Two-hundred-thousand of them are in camps in neighboring Chad.

The world body estimates as many as 10,000 Darfur residents are dying each month, in what it describes as the world's worst humanitarian crisis. The United States has gone further, classifying it as genocide.