The US has imposed sanctions on Iranian airline Mahan Air after accusing the airline of flying persons and equipment linked to an alleged plot to kill the Saudi Arabian ambassador to the US.

Under the sanctions, Mahan Air’s US assets will be frozen and US firms barred from doing business with the airline.

The sanctions were announced on 12 October, the day after US authorities announced they had foiled a conspiracy to assassinate the Saudi ambassador to Washington, Adel al-Jubair.

“Mahan Air’s close coordination with the IRGC-QF [Islamic Revolutionary Guards Corp-Quds Force] secretly ferrying operatives, weapons and funds on its flights, reveals yet another facet of the IRGC’s extensive infiltration of Iran’s commercial sector to facilitate its support for terrorism,” said US Treasury official David Cohen.

Iran has now summoned the Swiss ambassador to Tehran, who represents US interests in the country.

The US also imposed sanctions against five people it linked to the alleged assassination plot, including two people charged with criminal offences related to the plot, Manssor Arbabsiar and Gholam Shakuri.