The video lasted only 22 seconds but its message seemed clear, and Secretary of State Mike Pompeo wanted the world to know, so he posted it to Twitter for his 1.1 million followers.

“Iraqis — Iraqis — dancing in the street for freedom; thankful that General Soleimani is no more,” Mr. Pompeo wrote.

The video was authentic, but Mr. Pompeo’s description of it was exaggerated.

Witnesses in Iraq said that only a handful of men carrying Iraqi flags had run — not danced — along a road while the voice of a man speaking near the camera was heard praising the killing of Maj. Gen. Qassim Suleimani of Iran in a targeted United States airstrike on Friday at Baghdad International Airport.

The man whose voice is heard in the video exclaims that General Suleimani’s death has avenged the deaths of Iraqis protesting Iran’s presence in their country.