Religious leaders said the singer's decision to perform in the country on a holy day brought bad luck.

Church officials were outraged by the singer's plans to stage her Sticky & Sweet gig in the capital Sofia on 29 August - the day Orthodox Christians mark the beheading of Saint John the Baptist with a fast.

But despite protests, Madonna refused to reschedule the date and religious leaders are convinced her defiance of their sacred customs led to the disaster on Macedonia's Lake Ohrid.

Speaking to the Daily Telegraph, church leader Nikolay said: "The catastrophe in Macedonia in which 15 Bulgarian citizens died was a sign from heaven. The Orthodox Church had called for people not to enjoy themselves on the day marking the execution of John.

"We should not allow the young to have fun on a day that should be dedicated to spiritual reflection."