Mahan Air, a private Iranian airline banned by Saudi Arabia and sanctioned by the U.S. for allegedly helping Hezbollah, has applied for a permit to fly twice weekly between Tehran and Johannesburg.

The route will not be going through Saudi Arabia, Gulf News reported.

The airline’s application is still being processed and the South African Department of Transport is waiting for outstanding documents from Mahan Air, DOT spokesman Motlatsi Lebea said, according to Tourism Update.

Established in 1992, Mahan Air flies to the Middle East, Far East, Central Asia and Europe, and it’s expanding.

The U.S. Treasury Department imposed sanctions on Mahan Air in 2011 for providing financial, material and technological support to Iran’s Revolutionary Guard and Hezbollah, Gulf News reported.

In April 2016, Saudi Arabia’s aviation authority said it had banned Mahan Air from using its airports and air space over safety concerns.

The authority cited “violations of national regulations related to safety of international carriers.”

Saudi Arabia severed all air links with Iran in January after the two countries cut diplomatic ties following Riyadh’s execution of Saudi Shiite cleric Nimr Al Nimr, Gulf News reported.

Mahan Air was also accused of flying the Quds Force in the Islamic Republic Guard Corps in a plot to kill Saudi Arabia’s former ambassador to the U.S., Adel al-Jubeir, International Business Times reported.

International sanctions on Iran were lifted earlier this year. During a two-day visit in April, President Jacob Zuma and Iranian President Hassan Rouhani agreed to increase non-oil trade and investment between South Africa and Iran to $1 billion dollars by 2020, according to Tourism Update.

The two countries signed eight bilateral trade agreements in trade and industry, energy, mining, agriculture, water resources, co-operation in intelligence gathering and anti-money-laundering initiatives.

Mahan Air has carried arms and Islamic Revolutionary Guard Corps military personnel to Syria in hundreds of recorded flights, according to U.S. political website The Hill:

Because of its role as Iran’s enabler for Syrian President Bashar Assad’s war effort, Mahan will not benefit from the sanctions relief provided under the Iran nuclear deal reached in July. Regardless, Mahan uses its commercial fleet to support Tehran’s regional proxy wars while easily buying planes from European suppliers and getting ground services at foreign destinations.

The U.S. Commerce Department has intercepted several third parties attempting to sell to Mahan Air, but it can’t stop every transaction, IBTimes reported. That’s because it’s in the U.S. interest to look the other way, some analysts said.

As the airline expands, analysts said the U.S. is having trouble keeping up:

Aviation records maintained by a private registry show that on Oct. 15 Mahan Air bought a jet at the center of an investigation from Anton Grundlingh, who registered the plane in South Africa. Grundlingh is the director of three aircraft-affiliated companies and a shareholder in a financial-services firm in South Africa. Records show he is also a shareholder in a U.S. company in Dallas.

Hilton Worldwide Holdings Inc., a major holding of the global investment firm Blackstone Group L.P., hosted Mahan crew members in Malaysia in 2013, according to U.S. Securities and Exchange Commission records. And American Express Global Business Travel booked tickets on Mahan Air.

A new airline, Nasim Air, is funded by Mahan, Iranian media have reported, according to IBTimes.

Despite U.S. threats to impound the sanctioned airplanes, Mahan is operating them, without fear of reprisal, on international routes that include European destinations such as Milan, Munich and Athens, Greece. Three of them were also used at least once recently to ferry weapons to Syria.

International Business Times tracked several Mahan Air flights over the span of two days and found at least two flights that took off from Damascus, landing in Al-Hasakah, Syria, the site of intense fighting between the Islamic State group and regime forces and their allies, before flying back to Tehran.