Photos published by Arab media outlets over the weekend that allegedly show American-made armored vehicles being used in a Hezbollah military parade could result in the United States providing less aid to the Lebanese Army.   

The images taken in the Syrian city of al-Qusayr were circulated by media sources in close association with the terrorist group to demonstrate their military prescence in the region. They depict the armored personnel carrier known as the M113 used frequently by the U.S. military to carry troops and artillery, triggering confusion about whether the weapons had links to the U.S. government, the Washington Post reported Wednesday.

The U.S. is monitoring the possibility that the images could signify the terrorist group was acquiring weapons from the U.S. supplied Lebanese Army, RT reported. State Department spokesperson Elizabeth Trudeau said if inquiries found that American arms were in the hands of the terrorist group, it would be a "grave concern."

“Our embassy in Beirut is working with the Lebanese armed forces to investigate the images circulating on social media purporting to show Hezbollah displaying US military equipment in Syria,” said Trudeau.

The Lebanese Armed Forces denied the U.S. made weapons were taken from the military.

“The photos of vehicles circulated by media outlets were not taken from the army and do not belong to the military,” the Lebanese Armed Forces said in a statement.

Charles Shoebridge, a security analyst and former counter-terrorism intelligence officer in the United Kingdom, said the Lebanese Army was the most likely source of the U.S. arms.

“Certainly the finger would seem to point… at the Lebanese Army, because many of them (M113) were supplied to them,” said Shoebridge.

The Lebanon Armed Forces received 50 armored vehicles, 40 artillery pieces and 50 grenade launchers from the United States this past summer, the Jerusalem Post reported.

The United States has a history of its arms falling into the possession of extremist groups in the Middle East after various military operation in countries like Iraq, Afghanistan and Syria. Most recently, news reported claimed the Islamic State group has acquired American missiles originally intended for the U.S.- backed militias they were fighting.