The children's parents were awakened in a downstairs bedroom by a smoke alarm around 1 am on Tuesday, but escaped without injury, investigators said.

Fire Chief Dan White said the staircase in the one floor home was so narrow he had to turn sideways to get through to the second floor.

The cause of the blaze was under investigation. Police seized a space heater and a small amount of what appeared to be methamphetamine from the home after the fire had been extinguished, White said. Police said it didn't appear the home was being used to manufacture the drug.

'In no way did the manufacture or possession of any drug contribute to the fire,' said Bentonville police Lt. Jon Simpson.

'We believe the fire is accidental. We believe the fire might be related somehow to a space heater.'

The five children ranged in age from 5 years to 13 years old.

Bentonville is about 240 kilometres northwest of Little Rock. -- AP