ALFRED de MONTESQUIOU, CASABLANCA

Police yesterday detained the owner and manager of a Casablanca mattress factory that went up in flames and killed 55 people.

Adil Moufareh, and his son Abdelali, the plant manager, were being questioned about poor security at the factory.

Workers say some doors were blocked during the blaze on Saturday at Hay Hassani, an industrial district.

Six people remained in hospital yesterday as the search for bodies continued.

Casablanca's governor, Mohamed Kabbaj, attributed the high death toll to the large number of people working in the factory at the time: 100.

The windows of the four-storey building were barred. An emergency exit was blocked, according to the head of the rescue operation, Jawad el Mejdoubi. He said firefighters also arrived two hours after the blaze began.

The discovery of another body yesterday placed the death toll at 55.

"I don't think we realised how big the fire was," el Mejdoubi said in the emergency ward of Ibn Rochd Hospital, describing "twisted bodies, faces disfigured by fire".

The fire was the North African kingdom's worst since a blaze killed 50 prisoners in a jail in 2002.

An angry crowd outside the factory accused the owner of blocking the exits.

Interior Minister Chakib Benmoussa said an investigation would examine security measures and conditions at the factory.

The minister said chemicals in the building sent the blaze out of control and delayed the rescue effort by hours.

Firefighters said many victims were trapped in the stairwell. A 29-year-old woman who escaped said many deaths occurred on the third floor, where women sewed.

"We ran to the door. It was blocked. To the lift - it was blocked. Then the lights went out," said Rachida Darif.

She saved herself by crawling through a space that led to the roof.-AP