Barcelona - One of the 18 people who were in a critical condition following a gas explosion in their block of flats in north- eastern Spain died on Thursday, regional health officials said.

The 60-year-old woman had burns to 85 per cent of her body.

Twenty-two of the 27 injured victims remained at hospital. They included eight children, five of whom were described as being in a very serious condition.

A gas explosion caused a three-storey building to partially collapse and sparked a fire in the low-income locality of Gava near Barcelona on Wednesday.

Police were investigating the nature of the explosion and whether it was linked to a burst water pipe. (dpa)