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MANAMA, Jan 7 (Reuters) - The U.S. Navy's Fifth Fleet said two F/A-18 fighter aircraft crashed during operations in the Gulf on Monday, but there were no fatalities.

"Teams from USS Harry S. Truman (CVN 75) rescued all three aviators after two F/A-18 Super Hornets crashed during operations in the Arabian Gulf Jan. 7," it said in a statement. "The cause of the accident is under investigation."

The Bahrain-based Fifth Fleet said the planes' crews were back aboard the aircraft carrier, and were reported in good physical condition after ejecting.

The aircraft were providing close air support from Iraq when they crashed, it said.

The aircraft were part of the strike group of the nuclear aircraft carrier, which is in the region as part of a routine presence of U.S. warships in the Gulf, it said.

The Pentagon said earlier on Monday that five Iranian boats made aggressive manoeuvres and showed hostile intent towards three U.S. navy ships at the weekend in the Strait of Hormuz, a major oil shipping route in the Gulf.

The Pentagon said the incident was serious but the Iranian foreign ministry described the incident as ordinary. (Editing by Charles Dick)

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