Twice as many foreigners as last year gathered in Pyongyang on Sunday for the city's annual marathon, tour companies said, as reduced tensions see visitor numbers rise in isolated North Korea. The event – part of the celebrations for the anniversary of founder Kim Il Sung's birth in 1912 – is the highlight of North Korea's tourism calendar and offers the chance to run or jog through the streets of the tightly controlled city. Around 950 Westerners entered the event, according to market leader Koryo Tours, compared to some 450 last year when numbers slumped. That brought participation almost back to the levels of 2017, before tensions soared as North Korea carried out a series of missile launches and leader Kim Jong-un traded threats and personal insults with US President Donald Trump. The same year, Washington also banned its citizens from visiting North Korea following the death of Otto Warmbier, a US student jailed for trying to steal a propaganda poster who died in a mysterious coma days after his release. Several other countries subsequently raised their travel warnings, a combination of events that dealt a significant blow to North Korea's tourism industry. The US ban remains in place but more Western tourists signed up for the marathon this time, tour operators said, following a year of high-level diplomacy between Mr Trump and Mr Kim. "As political tensions have subsided, tourism demand has increased," said Elliott Davies, director at Uri Tours, another operator. "You could plot a graph in this direct relationship." The vast majority of tourists to North Korea are Chinese and some 5,000 Westerners a year used to visit the country – with about 20 per cent of those from the US – seeking unique adventures in one of the most closed countries in the world. The annual race also attracts so-called "Marathon Chasers" who tick off runs around the world, said Matt Kulesza, a senior tour guide at Young Pioneer Tours. Angel Arnaudov, a 34-year-old engineer from Macedonia, said Pyongyang came on to his "radar" after finishing more than 30 marathons in cities ranging from Tokyo, New York and Copenhagen. "I want to experience the life in North Korea myself and see if it is like they say on TV or different," he said, adding he would be posting videos on his YouTube channel. For third-time participant Jasmine Barrett, the Pyongyang Marathon was an opportunity to interact with ordinary North Koreans who line the streets to cheer on the runners, offering high-fives and posing for selfies. "I keep coming back because I love to see the smiles on the children's faces," the Australian entrepreneur said. "I'd definitely recommend it to others because it's a great way to see the city and the people who live there." Tour operators advise visitors to take extra precautions about "what to do and what not to do" when travelling in the country. Simon Cockerell, Koryo Tours' general manager, said: "This is vital when visiting North Korea and anyone wanting to travel shouldn't go without a briefing."