Tehran | A fire broke out at a drug rehabilitation centre in northern Iran on Friday, killing at least 27 people, state media reported.

Seventeen others were injured and taken to hospitals in Langroud city, about 200 kilometres northwest of the capital, Tehran, state TV said.

It said the fire started at the private rehabilitation centre early Friday morning, and showed a video of flames and smoke pouring into the dark sky.

The fire was extinguished, and authorities are investigating the cause, it said.

Such accidents are not rare, mainly because of the disregarding of safety measures, aging facilities and inadequate emergency services.

In September, a fire broke out at a car battery factory owned by Iran's Defence Ministry for the second time in less than a week. There were no reports of casualties.