A man suffering liver disease and his wife tried to kill themselves by burning charcoal at their home in Sha Tin after recording a message on a cassette tape. They were found lying unconscious in bed at about 1.30am yesterday when the man's sister, 29, saw smoke coming out of their bedroom in Cypress House, in Kwong Yuen Estate, and opened the door with a spare key.

Emergency crews were called in and found a charcoal stove inside the bedroom. The couple were taken to Prince of Wales Hospital where the man, 36, was in a critical condition and his wife, 29, was in a serious condition last night.

A police spokesman said that on the recorded message, the couple claimed they wanted to kill themselves because of his illness. His sister told police the couple were also in financial difficulties.

In a separate case, a woman, 36, was recovering in hospital after she burned charcoal in a suicide bid at home in Pan Hoi Street, Quarry Bay, at 8am.

She was in a satisfactory condition in Eastern Hospital last night.

Police said the woman, who lives alone, tried to kill herself because of problems with her boyfriend.

The two charcoal-burning cases came as Hong Kong's two top supermarket chains - Wellcome and ParknShop - were preparing to hold talks with suicide-prevention experts about possible restrictions on sales of barbecue charcoal.

Charcoal-burning is now the second most common means of suicide in Hong Kong after jumping from high buildings.

Meanwhile, another woman survived after jumping out of her sixth-floor flat in North Point yesterday. The 34-year-old was found lying unconscious on the first-floor platform of Healthy Garden on King's Road at 8.30am.

She was taken to Eastern Hospital where she was in a serious condition. Her husband, 43, told police she wanted to commit suicide because she was ill.