Fifteen people have died of heart attacks and heat exhaustion as they sat in a horror traffic jam at an Indonesian road junction known as Brexit, reports Daily Mail.

Traffic snarled back for miles at the exit road at Brebes, in Central Java, from which it earned its local name of Brexit.

Trapped in cars and buses in scorching temperatures, passengers and drivers passed out and the death toll began to steadily rise with people reluctant to leave their vehicles as the line of traffic inched forward hour by hour.

Local media reported 13 people had died in the same day at the Brexit junction but the Indonesian Health Ministry said 15 people had died over three days.

But the death toll, which coincided with the start of the Eid al-Fitr religious holiday, has shocked health officials who have warned vulnerable people such as adults with heart problems and children not to undertake the journey until the congestion has eased.

Achmad Yurianto, head of the Health Ministry's crisis centre, told the Jakarta Globe varied risk factors had resulted in the deaths of holiday travellers.

He said: 'Fatigue and dehydration are among the fatal elements that can cause deaths, especially among vulnerable groups of children and parents.

'In addition, a vehicle's small and closed cabin with extensive use of air conditioning will lower the oxygen rate and increases CO2.' 

The ministry is so concerned about the rising death toll it has set up an emergency medical line specifically to cope with calls from motorists in distress as they sit in traffic jams.

The Globe said private vehicles and buses were locked down at the Brexit junction for hours.