Jordanian police spokesman Amer al-Sartawi said the shooting wounded one guard in the hand and the other in the leg. He described the shooting as an accident, but did not elaborate.
Edgar Vasquez, a spokesman for the US State Department's Bureau of Near Eastern Affairs, said the incident happened as guards were moving between vehicles outside of the embassy.
"A gendarmerie officer's weapon accidentally discharged inside the vehicle, injuring two officers," Vasquez said. "We understand the incident has been ruled an accident and the government's investigation has been closed."
Jordan is a main ally of the US in the Middle East.
However, the embassy there has been the scene of protests in the past over US policy in the region.