Senior U.S. officials revealed Thursday that security threats have been made against top Pentagon authorities not only when traveling outside the U.S., but when on American soil.

Frist reported by NBC News on Thursday and verified for Fox News by a senior Department of Defense representative, security officials believe the threats made could be linked to the killing of Iranian Gen. Qasem Soleimani by American forces in January, though definitive links could not reportedly be made.

The names of the Pentagon officials were not released, but they are believed to have been senior leadership involved in the operation that oversaw the takedown of Soleimani. Military leaders have also reportedly been targeted.