From her bedroom window, she saw thick black smoke rising from the flat below.

'I quickly called the police while I told my husband to check downstairs,' the woman, who wanted to be known as Madam Lu, recounted.

'Then my husband heard two explosions and said we had to evacuate,' she added.

The fire gutted a four-room flat on the 10th floor in Block 612 Ang Mo Avenue 4.

No one was home when the fire broke out at around noon. Firemen had to force their way into the unit, donning breathing apparatus sets.

Using two water jets, they put out the fire in 10 minutes.

The fire destroyed everything in the flat, as well as the air-conditioning unit outside Madam Lu's bedroom window.