Three patients died in a fire that broke out early Sunday on a coronavirus ward in a hospital in southeast Bulgaria, the rescue services said. The three male patients, aged 66, 70 and 81, were all ill with Covid-19 and died on the fourth floor of a hospital in the city of Sliven, the head of the local rescue services, Vladimir Demirev, told Bulgarian television. Six other patients on neighbouring wards had to be evacuated. The incident occurred as the EU member headed to the polls for the third time this year on Sunday amid the deadliest wave of Covid-19 yet in the country. “The most likely cause of the fire was a lit cigarette of one of the patients,” the Bulgarian health ministry said in a statement. Bulgaria’s hospitals, frequently run down, are currently overwhelmed by the number of coronavirus infections. With only just over 23 percent of the total population of 6.9 million people fully vaccinated, Bulgaria has the lowest vaccination rate across the European Union. After two previous elections in April and July returned fractured parliaments where parties failed to cobble together a coalition, the new election is not expected to bring about a stable government. The current interim administration has failed to impose stricter measures and prevent new infections and deaths from spiralling. Last week in neighbouring Romania, two Covid-19 patients also died in a hospital fire.