MOSCOW (Reuters) -Russian officials said on Tuesday that Ukraine had attacked Crimea with U.S.-produced Army Tactical Missile Systems (ATACMS) in an attempt to pierce Russian air defences of the annexed peninsula but that six had been shot down. Washington secretly shipped the long-range missiles to Kyiv as part of a $300 million military aid package for Ukraine that U.S. President Joe Biden approved on March 12, a U.S. official said last week. Whether to send the ATACMS missiles with a range up to 300 km was a subject of debate within the Biden administration for months.