The United Arab Emirates denied on Tuesday that it had supplied a Libyan armed group with powerful American-made missiles, after a Democratic senator warned that Washington could halt all arms sales to the United Arab Emirates.

On Friday the State Department said it had opened an investigation into how the weapons — four American-made Javelin armor-piercing missiles, normally sold only to close American allies — had found their way into a cache of arms discovered last week at a rebel base south of Tripoli.

The seized weapons included a number of Javelin anti-tank missiles, GNA military spokesman Mohammed Qununu said, with markings on the missiles’ shipping containers stating they belonged to the “Armed Forces of the United Arab Emirates”.

Libyan media also aired footage that appeared to show markings indicating the US-made weapons were originally sold to the UAE – a major buyer of American arms and one of Haftar’s main international supporters – in 2008.

Via Al Jazeera/ New York Times