AMMAN, JORDAN, NOV. 1 -- Iraqi President Saddam Hussein today ordered the release of four more American hostages in the face of U.S. charges of maltreatment of the captives.

The four men are sick and elderly, Information Minister Latif Nassif Jassim told a Baghdad news conference. He said Saddam had responded to a humanitarian plea from representatives of an unidentified Arab-American organization visiting the Iraqi capital.

Jassim identified the men as Randall Traini, Ramon Calles, Michael Bonner and Abdul Hamid Khanji, according to news reports from Baghdad. He gave no further information on the hostages, nor did he say when they would leave.

About 400 Americans remain captive in Iraq and occupied Kuwait, more than 100 of them held as "human shields" at potential military targets in the two countries.

Today, a U.S. diplomat in Baghdad gave reporters copies of two letters smuggled out from Americans held as human shields. "Please don't forget the 'guest' hostages," said the author of one, using the Iraqi euphemism for its captives. "I have been in the Iraqi gulag system for almost two months. We are virtually prisoners in Iraq."

The second writer said he had been moved five times to different targets, received no mail or messages and lost 35 pounds during his detention.

Reuter reported from London:

Amnesty International said it has evidence that Saudi forces detained and tortured hundreds of Yemenis, many over their country's stand in the gulf crisis, and it urged King Fahd to conduct a public inquiry.

"The victims are among the thousands of Yemeni nationals who were rounded up" since August, the human rights organization said.

It said Yemenis were singled out "for no apparent reason other than their nationality or their suspected opposition to the Saudi Arabian government's position on the gulf crisis."

Yemen has opposed the deployment in Saudi Arabia of a U.S.-led multinational force ranged against Iraq and condemned a U.N. trade blockade imposed on Baghdad for its invasion of Kuwait.

An Amnesty International team that went to Yemen said it saw people who had torture marks and interviewed a man beaten so badly he had to be hospitalized on his return.

The report said the Saudi government agreed to examine additional information submitted by the organization but did not believe there was "widespread violation" of its policy to treat Yemenis with "affection and dignity."

Amnesty International quoted Yemenis as saying that they were arrested on streets, in schools, at work or at home, some of them in night raids, particularly in Jiddah, which has the largest Yemeni population in Saudi Arabia.