At least 15 people are feared dead after an explosion devastated Gorni Lom gunpowder plant north of the Bulgarian capital, Sofia.

Civil defense force head Nikolay Nikolov said: “There are no signs of life at the site of the explosion.”

“After the examination we made, the hopes to find survivors have completely vanished,” said Nikolay Nikolov, Director of the General Directorate for Fire Safety and Civil Protection, Nova TV reported.

“We will still continue surveying and examining the perimeter with the hope to find survivors but I think that 13 men and 2 women have died in the blast. We have informed their relatives,” he said.

Three women employees who had been near the factory at Gorni Lom at the time were hurt and treated in hospital.

At least 15 people are feared dead after an explosion devastated Gorni Lom gunpowder plant north of the Bulgarian capital, Sofia

Rescue workers say they are unable to enter the site until Thursday evening because of the risk of further blasts.

However, interior ministry officials visited the factory overnight, defying orders, and said they found no survivors.

The explosion took place at around 17:00 on Wednesday, October 1, and a big secondary blast was reported at 21:45.

The factory, some 75 miles north of Sofia, destroys stockpiles of obsolete munitions for the Bulgarian army and Dnes daily newspaper quoted an expert saying it had been handling explosives from Greece.

The cause of the blast is unclear but reports say 10 tonnes of highly explosive chemicals were being stored at the plant.

Drones are due to fly over the area and the government has decided to send a team equipped with armored cars on to the site, local media report, although there is no indication when that will take place.

“The factory has been reduced to ashes,” an interior ministry spokesman said.

There were explosions at the factory in 2007 and 2010, in which several people were hurt. Two units of the plant were flattened in the 2010 blast.