BAGHDAD, IRAQ, SEPT. 2 -- The departure of more than 600 Westerners from Iraq early today has left behind a confused and menacing hostage crisis in which President Saddam Hussein still has a number of foreign captives to shield strategic targets from U.S. attack.

The uncertainty of the situation was dramatized by Iraq's withholding of landing clearance for a French airliner that was slated to fly into Baghdad tonight to take more European and American women and children to safety. Diplomats helping to arrange the flight said Paris is seeking to reschedule it for Monday.

But even with the evacuation of foreign women and children, as promised by Saddam last week, diplomats said an unknown number of U.S. and European men will likely remain in custody. According to Iraqi officials, some are being held at potential bombing targets to dissuade Washington and its allies from taking military action against Saddam to force him to leave Kuwait.

"Women are free to leave; men are not free, because the American administration is threatening Iraq with war," said the Information Ministry director general, Naji Hadithi, at a briefing for American reporters. "We believe that by holding these people in these installations, the war fever in the White House is reduced."

Hadithi's comment illustrated a mood of defiance that seems evident in Baghdad despite massing of U.S. and other forces in Saudi Arabia, almost universal condemnation of Iraq's attempt to absorb Kuwait and a trade embargo whose bite Iraqis say is beginning to be felt. Bread lines could be seen in the Iraqi capital today, and residents reported the beginning of shortages in some basic items, but no panic buying or hoarding.

Three more American men were picked up here Saturday after being lured from safe haven at the U.S. ambassador's residence. Iraqi authorities asked the three to come to government offices for visa formalities connected to their wives' departures, sources said, then took them into custody.

{Referring to this incident Sunday, a State Department spokesman in Washington said, "As long as complying with Iraqi directives can lead to immediate arrest, there is little room to place confidence in Iraqi promises."}

The three, employees of Bechtel, an American construction company, were among more than 100 U.S. citizens, mostly men on contract jobs here, who have sought shelter from arrest by staying at the ambassador's home, which is covered by diplomatic immunity and thus off-limits to Iraqi police.

European embassies also are sheltering their nationals from arrest by Iraqi police. Nevertheless, a half-dozen British men were taken into custody in the last several days under circumstances similar to those of the three Americans, reports here said.

A diplomat estimated that about 10 American men living in Iraq have been arrested since Saddam's government decided to use Western hostages as a shield against U.S. attack on strategic objectives, such as oil installations, military bases and factories.

Most of the other American men living here, from a community of about 400, have taken refuge in U.S. buildings covered by diplomatic immunity, he said. Only a handful have continued to report for work since the invasion one month ago.

"There are very few men out on work sites, and they would be unlikely to be picked up, because the Iraqis need them to do their jobs," the diplomat said.

Diplomats here say most of the foreign men sent to potential bombing targets came from Kuwait, not Iraq, but they have been unable to establish a solid estimate of how many are held. U.S. authorities have been unable to track about 600 American men resident in Kuwait before the invasion, out of a total U.S. community then of 2,500.

Many of the men are believed to be in hiding in occupied Kuwait, a diplomat said, while others may have escaped by driving to Saudi Arabia and then neglected to notify U.S. consular officials. Still others could have been picked up by Iraqi soldiers who have conducted house-to-house searches in Kuwait City's foreign-inhabitated neighborhoods, he added, while some may have perished in escape attempts across the desert.

Similar uncertainty surrounds attempts to count the number of Europeans held as shields.

Efforts by U.S. and other Western consular officials to get information from the Iraqi Foreign Ministry about the fate of these men have been met with silence. One diplomat suggested that the Iraqi government itself may not have an accurate count of arrested Americans and Europeans.

Iraqi authorities have told U.S. diplomats that Saddam's promise to allow women and children to return home also applied to Kuwait. But the exact number of them remaining in Kuwait is unknown, since many have stayed hidden along with the men in their families for fear of capture.

The overnight flights that arrived in Europe and the United States today contained a number of foreign women and children from Kuwait as well as some men allowed to leave for health reasons and picked up by civil rights figure Jesse Jackson during a visit to the occupied country.

Jackson left early today on an Iraqi Airways Boeing 747 that carried 199 Britons, 47 Americans, 22 French citizens and two Canadians, stopping in Paris, London and Washington. A Lufthansa Airbus that left about the same time carried 65 Americans and 251 Europeans to Frankfurt. Earlier, an Iraqi Airways jet flew 68 Japanese women and children to Amman.