An unmanned U.S. observation aircraft was shot down over Yemen on June 6, according to a statement by U.S. Central Command.
CENTCOM said the MQ-9 Reaper was shot down by Houthi rebels with a SA-6 surface-to-air missile that was enabled with Iranian assistance, according to the release.
A week later on June 13, the release said an Iranian SA-7 surface-to-air missile failed to shoot down an MQ-9 that was observing the M/T Kokuka Courageous, one of the two tankers that were attacked in the Gulf of Oman. The Reaper arrived minutes earlier at 6:20 a.m. at the M/T Altair, which was on fire, according to CENTCOM.
The release says the attack on the tankers were carried out by the Iranian Revolutionary Guard, which Iran has denied.
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
The CENTCOM statement appears to confirm reporting by media outlets that Iran tried to shoot down a U.S. drone around the time of the attacks on the tankers, as well as reports that a Reaper drone was shot down the week before by Houthi rebels in Yemen.
CNN reported Saturday that Iran launched a missile at a U.S. drone hours before the attack on the tankers, but failed to shoot it down.
Houthi rebels in Yemen released video footage and photos of what they claim was an MQ-9 that was shot down, according to BreakingDefense.