At least 27 people died in a massive fire that broke out at a drug rehabilitation centre in northern Iran early on Friday, the judiciary said.

“Twenty-seven have died and 12 others were taken to hospital after a fire erupted at a drug rehabilitation centre in Langarud”, a city in Gilan province north of Tehran, said the judiciary’s Mizan Online news website, quoting provincial chief justice Esmail Sadeghi.

The cause of the fire was not immediately clear but Sadeghi said an investigation “was under way,” according to Mizan, which said the centre could accommodate up to 40 people.

Local ISNA news agency shared footage of the fire which lit up the night sky and sent huge plumes of smoke into the air.

Other images showed the heavily damaged site after the fire was contained.

In August, a fire broke out in Tehran’s Grand Bazaar, damaging multiple shops but causing no casualties.

In January 2017, a fire at a 15-storey Plasco shopping centre in Tehran, killed at least 22 people, including 16 firefighters.