India, July 21 -- The US State Department has released a global security alert advising American citizens overseas to remain on high alert, citing concerns that Iran-backed or pro-Iran groups could target Americans as tensions between Washington and Tehran continue to intensify.

"Due to heightened tensions in the Middle East, the security environment remains complex with the potential for unforeseen escalation," the State Department said in an alert posted Saturday.

The advisory comes two days after an Iranian attack in Jordan killed two US service members and left four others requiring medical evacuation.

Although the notice specifically references the worsening situation in the Middle East, officials stressed that Americans across th...