A fire that broke out at a nightclub in North Macedonia where more than a thousand people had gathered for a concert killed at least 50 people, state news agency MIA reported on Sunday.

Citing the interior ministry, MIA said "at least 50 people died in a discotheque in Kocani", a town some 100 kilometres (60 miles) east of the capital Skopje, where "around 1,500 people attended a concert". AFP could not immediately confirm this information with the Balkan state's authorities.

The agency reported that the fire broke out in "Pulse", a nightclub in the small town with around 30,000 inhabitants during a concert by DNK, a hip-hop duo popular in the country.

The concert that started at midnight on Sunday was attended mainly by young people.

Online media outlet SDK reported that the fire started at 3 am (0200 GMT), and gave a tally of more than 100 injured citing rescue sources.

The wounded were taken either to the local Kocani hospital or to Stip, some 30 kilometres south of the town.

Local media speculated that the fire was probably caused by the use of pyrotechnic devices.