Just weeks after carrying out its fifth nuclear test, North Korea put on an unprecedented civilian and military air force display Saturday at the country's first ever public aviation show.

The two-day Wonsan International Friendship Air Festival was held at the newly refurbished Kalma Airport -- previously a military airfield -- completed last year to boost tourism in the area around the eastern port city of Wonsan.

The festival was already scheduled before North Korea conducted its fifth nuclear test on September 9, triggering international outrage and threats of still further sanctions against the deeply isolated nuclear-armed country.

The show kicked off with an aerial display by a US Hughes MD-500 military helicopter -- one of a number acquired in the 1980s by using a third country to circumvent US export restrictions.

North Korea's aviation industry was targeted by provisions in the UN Security Council resolution passed after its fourth nuclear test on January 6.

The provisions prevent member states selling or supplying North Korea with aviation fuel, aviation gasoline or naptha-type jet fuel or kerosene type jet fuel.

But a recent report by the Nautilus Institute for Security concluded that domestic supply of jet fuel was probably adequate to keep air force aircraft flying, especially given their very low annual exercise rate.

The Hughes helicopter was followed by an extended solo acrobatic display by the most advanced aircraft in the North Korean air force -- an early-model Soviet built Mikoyan MiG-29 Fulcrum which made several ear-splitting low passes over the crowd.

The rest of the air force fleet is largely comprised of antiquated Chinese built copies of the MiG-17, MiG-19 and MiG-21. Experts say the low number of flying hours and training their pilots receive compounds the air force's technical deficit compared to neighbouring South Korea.

North Korean airports are generally high security areas, but the Kalma tarmac and surrounding airfield were opened for the festival to several thousand local spectators, foreign media and several hundred slightly over-excited aviation enthusiasts from 20 countries.

- 'Flowers of the sky' -

A crowd highlight was a formation display of two Soviet-era MiG-21s piloted by North Korea's first two female jet fighter pilots.

The women, Jo Kum-Hyang and Rim Sol, shot to national fame last year when leader Kim Jong-Un dubbed them "flowers of the sky" after watching one of their training sessions.

"Even a 100 percent he-man would find it difficult to do that," the show announcer yelled in English over the loudspeaker as the two pilots banked their jets in a tight turn.

He then scolded the crowd as they surged towards the runway to wave to Jo and Rim as they landed.

Several foreign observers noted that the low passes by the MiG29 and later by a Sukhoi-25 fighter would have been forbidden at other international air festivals.

"You would never see that anywhere else in the world. Regulations prevent any passes or manoeuvres over the crowd line," said Peter Terlouw, a Dutch aviation photographer.

"But for us, it's brilliant!"

- 'Quite magical' -

As well as the promised military aircraft displays, a major draw was the presence of national carrier Air Koryo's vintage planes which operate on some domestic routes.

"To get this close to such old planes in a country like North Korea is very special," said Ashley Walker, 39, a British pilot based in Hong Kong with Cathay Pacific.

"You won't find working planes like these anywhere in the world," he said, gesturing to a twin turbo-prop Antonov AN-24 sitting on the tarmac.

"Modern civilian planes are so bland these days, but these are quite magical and really take you back in time," Walker said.

Walker was one of 200 enthusiasts brought to the show by British-based Juche Tours, with the promise of brief flights on some of the civilian planes, which also included an Ilyushin-18 and Tupolev-134.

"It's obviously the fact that it's in North Korea that makes it so special," said Canadian enthusiast King Hui, 63.

"I've been here once before and photo-wise the message was always 'no-military, no-military', and now we're getting to see this," Hui said.

Wonsan -- a traditional recreation area -- is currently the focus of a major tourism development plan in tandem with the nearby Mount Kumgang district.

Just 25 kilometres from Wonsan lies one of Kim Jong-Un's pet projects -- the Masik Ski resort completed in 2013.

Mount Kumgang was originally developed as a resort for South Korean visitors but Seoul halted all trips after a South Korean tourist was shot dead by a North Korean soldier when she strayed off the approved path.