A fire sparked by an electrical fault has killed 18 people and injured 43 others at a camp in Algeria, emergency services and the Red Crescent said.

The blaze began before dawn at the camp housing about 600 migrants in Ouargla, 800km (500 miles) south-east of Algiers. The emergency services rushed to the scene to extinguish the fire.

The authorities have opened an investigation. The victims’ nationalities were not immediately known.

“The fire broke out at 3am (0200 GMT), killing 18 people and wounding 43,” said Col Farouk Achour, a civil defence official.

The president of the Algerian Red Crescent, Saida Benhabiles, said the fire was sparked by a short circuit which triggered the explosion of a heater. She said 27 people were still being treated in hospital.

Since Libya descended into chaos in its 2011 uprising, Algeria has become a top north African destination for sub-Saharan people seeking a better life.

Benhabiles said more than 4,000 migrants from Niger had been returned to their country by Algeria since 2014. She said 400 more migrants were due to be sent back to Niger from Ouargla, but it was not clear if any of them were from the camp hit by the blaze.

According to Benhabiles, the migrants are free to come and go from the camp. “They are constantly on the move. One day there could be 2,000 (migrants) and the next they are 200,” she said.

“We don’t lock up people as they do elsewhere.”