The USS Vincennes, the cruiser that mistakenly shot down an Iranian airliner last month, rescued five Iranian fishermen over the weekend who apparently had been drifting in a dinghy for more than a week, defense officials said today. The officials, who asked not to be identified, said the guided-missile cruiser was on a routine patrol in the Gulf of Oman, just below the entrance to the Persian Gulf at the Strait of Hormuz, when it spotted the five fishermen in a small dinghy on Sunday. The men were quickly taken aboard and treated for what was described as minor injuries, primarily dehydration and hypothermia, the officials added. ``The five identified themselves as fishermen whose boat sank while working in the Gulf of Oman,'' said one source. ``They had apparently been adrift for several days, possibly up to eight days.'' The sources said the men were still aboard the Vincennes today, awaiting arranfements to be made for a return to Iran. The Vincennes took up patrol duties just outside the Persian Gulf not long after it accidently shot down an Iranian Air Bus on July 3, killing all 290 aboard. The guided-missile cruiser had just emerged from a battle with Iranian gunboats when its radar operators detected what crew members thought was an Iranian F-14 fighter. According to a Pentagon report which has not been released publicly, the stress of first-time combat contributed to crew errors in tracking and targeting the ill-fated airliner.