Commanders from Iran's Islamic Revolutionary Guards Corps (IRGC) and Lebanon's Hezbollah group are on the ground in Yemen helping to direct and oversee Houthi rebels attacks on Red Sea shipping, four regional and two Iranian sources told Reuters.
Tehran has provided advanced drones, anti-ship cruise missiles, precision-strike ballistic missiles and medium-range missiles to the Houthis, who started targeting commercial vessels in November, the sources said.
IRGC commanders and advisers are also providing know-how, data and intelligence support to determine which of the dozens of vessels travelling through the Red Sea each day
Washington said last month that Iran was deeply involved in planning operations against shipping in the Red Sea and that its intelligence was critical to enable the Houthis to target ships.
The Red Sea attacks fit in with Iran's strategy of expanding and mobilizing its regional Shi'ite network of armed militias to project its influence and show its ability to threaten maritime security in the region and beyond, two analysts said.
White House national security spokeswoman Adrienne Watson also said last month that Iranian-provided tactical intelligence had been critical in enabling the Houthis to target ships.
According to two former Yemeni army sources, there is a clear presence of IRGC and Hezbollah members in Yemen. They are responsible for supervising military operations, training and reassembling missiles smuggled into Yemen as separate pieces, the two people said.
Washington and Gulf Arab states have repeatedly accused Iran of arming, training and financing the Houthis, who follow an offshoot of Shi'ite Islam and are aligned with Tehran as part of its anti-Western, anti-Israel "Axis of Resistance" alongside Lebanon's Hezbollah and groups in Syria and Iraq.