Iranian carrier Caspian Airlines had a Boeing 737 seized at Istanbul Airport over a €3mn ($3.41mn) debt, Tabnak reported on September 29.

A Turkish court ordered the seizure on September 28 and passengers were made to leave the aircraft, said Majid Akhavan, spokesman for Iran's Civil Aviation Organisation. He said the debt relates to airport services. The creditor is ACM Temsil Gozetim, an aviation representation and supervision company, and the aircraft is registered EP-KPB.

The seizure follows a US sanctions drive that has cut Iranian airlines off from much of the region's airspace and airports. The US Treasury Department designated 27 Iranian airlines on September 8, covering the remaining carriers not already under sanctions, as part of its Operation Economic Outcast campaign against Tehran.

Treasury Secretary Scott Bessent said on September 21 that all Iranian airlines would be shut down worldwide from September 23. Airports and companies that supply Iranian aircraft with fuel, landing services or tickets risk secondary sanctions, which can cut non-US firms off from the US financial system, he said.

A wind-down period for servicing Iranian carriers expired on September 23. Oman, Azerbaijan and Georgia cancelled flights with Iran, and Iraq closed Najaf airport to Iranian airlines after barring them from Baghdad.

The United Arab Emirates suspended all flights operated by Iranian airlines. Flights to Turkey and parts of Asia have continued, the head of Tehran's Imam Khomeini International Airport said. Turkey has not barred Iranian carriers, and Iranian travellers have turned to overland routes through Turkey and Armenia.

Caspian said an administrative matter in Turkey has temporarily restricted the operation of one of its Boeing aircraft, and that legal and administrative steps to resolve it are under way. The airline said it has arranged measures to keep its flights running.

Caspian Airlines was founded in 1993 and is based in Tehran. It is under US Treasury sanctions.