North Macedonian authorities have detained 15 people and ordered a nationwide review of entertainment venue licenses after a nightclub fire left 59 people dead and 155 injured.

The inferno, sparked by stage pyrotechnics during a live concert at Club Pulse in the eastern town of Kocani, swept through the overcrowded venue in the early hours of Sunday.

Interior minister Panche Toshkovski said 15 people had been detained for questioning after a preliminary inspection revealed the club was allegedly operating without a proper license.

A woman cries outside a hospital in the town of Kocani, North Macedonia following a massive fire in a nightclub early on Sunday (AP/Visar Kryeziu)

“We have grounds for suspicion that there is bribery and corruption in this case,” he told reporters without elaborating.

He said the number of people inside the club was at least double its official capacity of 250.

People as young as 16 were among the casualties, and the nation declared seven days of mourning.

“We are all in shock, and I am shocked myself: as a mother, as a person, as a president,” North Macedonia’s President Gordana Davkova Siljanovska said in an address to the nation on Sunday night.

“I still cannot believe that the terrible tragedy in Kocani is a reality. I do not know with what words to express my condolences to the parents and loved ones of the deceased,” she said.

“No one responsible should escape the law, justice and punishment. Let us not allow anyone to endanger the lives of innocent people anymore.”

Authorities say they are investigating allegations of bribery surrounding the nightclub that was crammed with young revellers and at double capacity.

And North Macedonia’s government ordered a sweeping three-day inspection to be carried out at all nightclubs and cabarets across the country, starting on Monday.

The country was in mourning as people watched harrowing scenes in the town of 25,000 people, where rescuers for hours carried out their grim task of removing the charred bodies of clubgoers.

Girls cry as they light candles in the town of Kocani (AP/Armin Durgut)

The fire caused the roof of the single-storey building to partially collapse, revealing the charred remains of wooden beams and debris.

Anxious parents gathered outside hospitals in Kocani and the capital Skopje, some 72 miles west, eager for updates about the injured. Many of the most seriously injured were receiving treatment in Greece and other neighbouring countries.

Waiting outside the hospital in Kocani, Dragi Stojanov was among those who received the dreaded news that his 21-year-old son Tomce had perished.

“He was my only child. I don’t need my life anymore … 150 families have been devastated,” he told reporters.

“Children burnt beyond recognition. There are corpses, just corpses inside (the club) … and the bosses (of organised crime), just putting money into their pockets.”

Flags around the country have been lowered to half-staff, and the death toll may rise further, with 20 of the injured in critical condition, health minister Arben Taravari said on Sunday.

Although the investigation into the fire’s cause is ongoing, videos showed sparkling pyrotechnics on the stage hitting Club Pulse’s ceiling and igniting the blaze as a band played.

Condolences poured in from leaders around Europe as well as from the office of Pope Francis, who has been in hospital for a month receiving treatment for double pneumonia.