GORNI LOM, Bulgaria : Fifteen people were confirmed dead on Thursday in a blast that flattened a Bulgarian explosives decommissioning plant near the northwestern village of Gorni Lom the previous day, officials said. “Thirteen men and two women perished. The blast was so powerful that it left craters,” civil defence force director Nikolay Nikolov said, adding that the cause was probably “human error”. Police engineers were continuing to search the area, Nikolov said, adding however that the devastation was so complete that “no traces whatsoever of bodies could be seen” at the site. According to the plant’s management, 12 workers and three of the factory chiefs were inside the facility at the time of the blast, which happened as Greek landmines were being taken apart.  The explosion rocked the whole mountainous area and was heard in the nearby village of Gorni Lom, residents told state television. Many were reluctant to talk, having lost friends and relatives, but many others said the plant operated with outdated machinery and workers were paid less than the minimum salary of 340 leva (170 euros, $220).

“I used to work there and I smuggled inside the area long before the engineers arrived. Everything was razed to the ground,” Dimitar Dimitrov, 59, told AFP, slamming the authorities’ slow reaction after the accident.

His 26-year-old son Vasil, who was among the victims, was paid 240 leva and working conditions were bad, he added.

Six people were injured in explosions at the privately owned facility in 2007 and 2010, and labour ministry inspectors last month uncovered numerous problems and poor “technological discipline” there, for example with rubbish barring escape routes.

Bulgaria, the EU’s poorest country, has large amounts of ageing ammunition from the communist era that has been awaiting disposal, and similar incidents have multiplied in recent years.

The country’s main prosecutor has now launched an investigation into the latest disaster.

As Bulgaria prepares to vote in general elections on Sunday, all political parties cancelled their closing rallies for Friday when the country will hold a national day of mourning.