"They stopped our bus and told us to get out," an Iranian peasant said excitedly in the thick accent of his native Khorassan Province. "Suddenly we were surrounded by armed men. Then they told us to get on board one of their planes. We were standing in the middle of the road when a plane caught fire. A lot of dust flew up, and we started to run."

That, with some variations and embellishments, was the essence of the story told today by a group of Iranian bus passengers who said they were briefly detained by U.S. commandos on a desert road early this morning.

How much, if any, the capture of the bus passengers figured in a decision to cancel the U.S. mission to rescue the American hostages was not clear. But the riders' accounts of the bizarre events surrounding the American debacle indicated that the passage of their bus came as aircraft were landing at a desert staging point for a flight onto Tehran. This apparently injected further elements of confusion into an already troubled American operation.

Making the incident even more confusing were the passengers' descriptions of more men and machines than the U.S. government says were involved in the rescue attempt.

Interviewed on Iranian radio, one of the passengers said their bus was stopped by a plane on the road.

The passenger said soldiers carrying Iranian-made G3 automatic rifles with telescopic sights made them all get out of the bus, which was traveling between the northeastern city of Mashad and the central city of Yazd. It had reached a point about 100 miles southwest of the desert town of Tabas. i

The unnamed passenger said soldiers speaking Farsi, the Iranian language, told them to get into one of the U.S. aircraft, apparently a C130 transport plane.

"But the people in the plane didn't agree that we should go on board, so they took us back to the bus," the passengers said. "Then with the bus they took us to another plane that had just landed."

"But they didn't agree to let us go on that plane either," the passenger said. "Meanwhile, some helicopters were landing. While we were out of the bus, one soldier who was speaking on a walkie-talkie said in Farsi, 'Shall we kill them?'

"While the soldiers were talking with the people in the second plane about whether we could get on the plane or not, suddenly I heard an explosion and the plane started to burn. I didn't know how it happened. But when it exploded, we all ran away."

He said that the soldiers numbered between 400 and 500.

Another passenger said three Iranians were among the soldiers. He said he saw a jeep and motorcycles that apparently had been unloaded from one of the transport planes.

Another of the group of about 50 Iranians who were on the bus gave this account to the radio:

"Planes were landing at regular intervals. Seven to eight cargo planes and one helicopter. After a while, lots of people got off the planes. There was one motorcycle and a jeep. They took us to a helicopter that was still running. With the will of God, the plane caught fire. I don't know how. Then one of them told us to stay there until morning, and then they left."

One of the bus riders said that a few of the soldiers were black and that some spoke what he took to be French.

An Iranian Revolutionary Guard who arrived on the scene after the Americans left told the official Pars news agency that the co-driver of the captured bus resisted the first order to get out of the bus and was hit with a rifle butt.

"One of the commandos took the passengers back on the bus and drove [the driver] to one of the planes," the agency said. "A number of witnesses counted seven planes and eight helicopters."

Hours later, one of the aircraft was said to be still smoldering after a collision that U.S. officials said occurred after it had been decided to abort the mission because of equipment failures.

Despite the U.S. statements that all the commandos had left Iran, Revolutionary Guards and rural police reportedly were combing the area for Americans that officials here seemed convinced had been left behind.

The U.S. aircraft apparently flew up from the Gulf of Oman across the sparsely populated province of Baluchistan in southeastern Iran in an arc toward the point where they landed to refuel, judging by accounts from Washington and Tehran.

Although U.S. officials said that one transport plane and five helicopters were left on the site about 300 miles southeast of Tehran in the middle of the desert, Iranian President Abol Hassan Bani-Sadr said he saw five helicopters and two destroyed planes when he flew over the scene today.

There was no information here pinpointing where the U.S. rescue mission originated, but Europeans diplomats said that Oman seemed a likely candidate.

Diplomats here speculated that he may have been confused by the wreckage of one of the transport planes and a helicopter, which were said to have collided while taking off in the dark.

An Iranian military official said that at least one of the five helicopters, which he identified as Cobra gunships, was sitting on the ground with its rotor turning when Iranian security forces arrived on the scene this afternoon.