Several hundred Westerners, including at least 28 Americans, have been taken from hotels in Kuwait and transported by bus to the Iraqi capital of Baghdad, where their status remained unclear last night, diplomatic officials said.

A senior U.S. official said the government did not have enough information to suggest that the Americans are being held against their will or are endangered. But the official said the instability of the situation in Kuwait and Iraq and the U.S. assessment of Iraqi President Saddam Hussein's "belligerence" are causing serious concern.

There was still no word on the fate of an estimated 3,800 Americans living in Kuwait. The State Department yesterday called in Iraq's ambassador to the United States, Mohamed Sadiq Mashat, to warn that his government would be held responsible for their safety.

Many among the group of Britons, West Germans and Americans taken to Baghdad had apparently arrived in Kuwait as passengers aboard a British Airways 747 that originated in London and was stranded by the Iraqi invasion when it landed to refuel and change crews on its way to India and Malaysia.

British Airways refused to release a list of passengers and State Department officials said they had not been able to determine whether the Westerners had been taken to Baghdad as hostages.

"We view this particular matter, obviously, very seriously," said State Department spokesman Margaret Tutwiler. "The president has made clear to the Iraqi government its responsibility to safeguard the lives of those who wish to leave. We hold Iraq responsible for the safety of Americans and all foreign nationals."

The U.S. statements echoed similar protests yesterday by the West German and British foreign ministries and followed a warning Sunday by Iraq that foreign countries should take into account the safety of foreign nationals in Kuwait when contemplating punitive measures against the invading country.

In addition to the airline passengers, 11 U.S. oil field workers who had been stationed in the path of the invasion also have been taken to the Sheraton hotel in Baghdad, where they were visited over the weekend by U.S. diplomats, officials said.

Kuwait relies heavily on foreign workers to sustain its prosperous, oil-based economy. In addition to technicians, engineers and other oil field specialists, Americans in the desert sheikdom include teachers, university professors, bankers and the wives of Kuwaiti citizens who studied in the United States, according to Francois Dickman, who served as U.S. ambassador to that country from 1979 to 1983.

Among the oil field workers taken to Baghdad was 52-year-old Rainard Walterscheid, who was working on an oil rig adjacent to the Iraqi border and was several weeks away from finishing a shift that would allow him to return home to Jacksboro, Tex., according to his daughter-in-law.

Connie Ogle said her father-in-law has worked in the oil business for decades, including stints in Egypt and Iran, and had worked in Kuwait since March. "He liked it," she said. "This was his life."

A British Airways spokesman said that the 747 was carrying 367 passengers when it landed in Kuwait after a seven-hour flight from London at 2 a.m. last Thursday, about the same time that the Iraqi invasion shut down the airport.

The plane, en route to Madras, India, and Kuala Lumpur, Malaysia, had been scheduled to spend barely an hour on the ground to pick up a fresh crew and fuel, according to the spokesman, John Lampl. "People were getting on and off," Lampl said. "One crew got off and another was getting ready to get on."

After the airport was closed, passengers were transported to hotels in Kuwait City where they remained for an unknown number of days before most of them, if not all, were taken to Baghdad by bus. In addition to the Americans, passengers included four French citizens, four West Germans, two Italians, and a Spanish businessman.

"The Iraqi forces are singling out nationals of four countries -- the United States, Britain, France and West Germany," said Hanns Schumacher, spokesman for the Bonn Foreign Ministry.

In Washington, State Department officers staffed a phone bank to provide information to friends and relatives of Americans living in Kuwait, a country with a reputation for being relatively hospitable to Westerners, with well-stocked stores, modern highways and comfortable apartment complexes.

"Kuwait's a very friendly place," said Patricia Hale, of Spring, Tex. She had planned to join her husband, Edward, an oil rig worker, in a few weeks. "It's just a nice place to live."

Staff writers Michael Ybarra in Washington and Marc Fisher in Bonn contributed to this report.