Mexican authorities say children were left home alone by parents who had gone out to work.

Seven children have died following a house fire in a poor Mexico City neighbourhood, according to Mexican officials.

The city prosecutors’ office said on Friday that six young children and one older child died in the early morning blaze in the Iztapalapa neighbourhood.

The official said the children were apparently left at home alone while their parents worked.

It was not known what caused the pre-dawn blaze at the sheet metal-and-cardboard shack in the densely populated area on the sprawling capital’s east side.

House fires in the city are often caused by attempts to heat dwellings using wood or charcoal fires, or faulty gas connections.

The fire was similar to another less than a month ago that was caused by a gas leak, said the top city official for the area, Clara Brugada.

“We’re going to investigate (what caused the fire), but we will have to launch a campaign on how to use gas heaters safely in the winter,” she said.

Iztapalapa is the most populous area in Mexico City, with 1.8 million inhabitants, many of them living in destitute conditions. The capital’s metropolitan area is home to more than 20 million people.