US intelligence warns Iran escalating efforts to target American personnel

US National Intelligence Director Jay Clayton has warned that Iran has "substantially increased efforts to target US personnel" in the Middle East and other regions, according to a memo seen by the BBC. The warning comes as the State Department adjusts staffing at diplomatic posts, including the ordered departure of non-emergency embassy staff from Saudi Arabia. The staffing changes follow escalating Houthi attacks on Saudi Arabia, which have killed at least 21 people since October, including a deadly missile strike on Riyadh's airport that killed 13. Clayton's unclassified memo, sent to Secretary of State Marco Rubio, said Iranian lethal plotting against US citizens has reached "advanced stages" in multiple countries. The Houthis say their attacks retaliate against a Saudi blockade and an air strike on Sanaa airport. The conflict stems from Yemen's civil war, which began in 2014, and has intensified amid a wider US-Iran confrontation that included a February air campaign and the closure of the Strait of Hormuz.