CAIRO — Houthi rebels in Yemen on Monday released an American freelance journalist who had been in their custody for about two weeks, the State Department and the journalist’s family reported.

The journalist, Casey L. Coombs, one of several Americans believed to be held by the Houthis, was freed as a video was released and published online of Isabelle Prime, a Frenchwoman seized three months ago. The video shows her pleading with the presidents of France and Yemen to help secure her release from her captors.

Ms. Prime, 30, a consultant for a World Bank-financed project, is not believed to be held by the Houthis, and may be held captive by a group aligned with Qaeda militants in Yemen.