DHAHRAN, SAUDI ARABIA, SEPT. 17 -- Iraqi authorities refused today to allow Kuwaiti men between the ages of 17 and 45 to flee to Saudi Arabia, slowing the flow of Kuwaiti refugees here to a trickle, Saudi officials said.

Immigration authorities said fewer than 50 cars passed into the Saudi town of Khafji today through a border crossing that Iraqi authorities in occupied Kuwait had unexpectedly opened Friday. During the weekend, an estimated 7,000 fleeing Kuwaitis took advantage of the opening.

Refugees arriving in Khafji and traveling south to Dhahran said Iraqi troops were ordering men trying to leave the country to get out of their cars and in many cases forcing the women accompanying them to continue alone.

{News agencies quoted refugees as saying they feared the men were to be conscripted into the Iraqi army. Refugees said the ages of those detained match the age limits that Iraqi law applies for conscription to the army in case of a national emergency. Iraq imposed its laws in Kuwait following its Aug. 2 invasion.}

In Kuwait, the refugees said, Iraqi authorities were ordering Kuwaitis to shave their beards. Many Islamic fundamentalist groups direct men to wear beards to emulate the prophet Muhammad, and secular governments such as Iraq's, often discourage them.

Refugees said Iraqis also were ordering Kuwaitis to exchange their license plates for Iraqi plates. They said shopkeepers were being told to open for business or face the confiscation of their goods.

Soldiers at Iraqi checkpoints throughout the Kuwaiti capital have given Kuwaitis a three-day deadline, until Tuesday, to meet the new requirements, according to the refugees crossing into Saudi Arabia.

"In the last two weeks they have become very nervous, maybe because of the Kuwaiti people who are resisting them," according to one refugee who, like most, spoke on the condition of anonymity.

Iraqi soldiers are raiding private homes for food and are even asking fleeing Kuwaitis at checkpoints for something to eat, another said. "At checkpoints, we gave them cheese, we gave them bread. All of them said, 'Please, it's not our fault,' " this refugee added.

"They are completely destroyed," yet another refugee said of the Iraqi troops. "They say, 'We don't know what is our mistake. We don't know why our ruler, why he is doing this.' "

In Washington, the Bush administration expressed concern about reports that Iraqi border guards were confiscating the passports and other identity papers of the Kuwaiti citizens fleeing through the crossing at Khafji. State Department spokesman Richard Boucher called the confiscation "an ominous sign."

"The fact that people leaving are having their travel documents taken away seems to be an implication to us that they might not be allowed to return," he said. "If this is part of an Iraqi effort to drive Kuwaitis from their homes, it is unacceptable."

Boucher added that "we strongly object to any move which would deny citizens and legal residents of Kuwait the right to return to their homes and jobs when the situation stabilizes."

Saudi Arabian officials, meanwhile, already straining to accommodate the more than 200,000 Kuwaitis and other foreign nationals who have fled south in the weeks after the Aug. 2 invasion, braced for the latest wave of immigrants.

Hotels in Dhahran and Riyadh are already full of Kuwaiti families, and Kuwaitis who drove into Dhahran Monday were being told to go on to Jiddah, on the other side of the country, to find accommodations.