Heat-related illnesses cause 12 runners to fall during the race near South Korea’s Demilitarized Zone.

Eight runners were taken to hospital with heat-related illnesses after a marathon near South Korea’s Demilitarized Zone with North Korea took place amid record temperatures, local authorities said.

Temperatures approached 30C (86F) for Sunday’s race as much of the Korean Peninsula baked under a warm front more akin to summer than its typically mild spring weather.

The DMZ Peace Marathon in the city of Paju allows participants to test their mettle on a course running close to the highly sensitive area that separates South and North Korea.

Emergency services received reports around 10:30am (01:30 GMT) that participants were collapsing along the race route in Munsan, a town within Paju, according to fire officials, local reports said.

Twelve runners fell ill, including suffering convulsions, dizziness and hyperventilation, officials told the AFP news agency on Monday.

Eight were taken to hospital, including a 43-year-old who needed intensive care. 

Authorities said the stricken runners appeared to have pushed themselves despite the rising heat.

A fire official urged people to look out for signs of heatstroke and “stop exercising immediately and cool down” if they occur.

In the capital, Seoul, about 30km (19 miles) from Paju, temperatures hit 29.4C (84.9F) over the weekend, the highest in mid-April since modern record-keeping began in 1907.

The Korea Meteorological Administration told AFP that the heat spike was likely caused by a temporary weather system drawing warm air northwards, a pattern sometimes seen during spring.