US woman Diana Nyad attempts Cuba to Florida swim

A 62-year-old American woman is making her fourth attempt to become the first person to swim from Cuba to the US without the protection of a shark cage.

Diana Nyad has already been stung several times by jellyfish but is continuing her 166km (103 mile) journey, team members said.

She left the Cuban capital, Havana, on Saturday afternoon and is aiming to reach Florida on Tuesday.

She is relying on an electronic shield as a shark deterrent.

Nyad, who first attempted to swim in 1978, is hoping to become the first person to set a record crossing of the Florida Straits unaided.

The long-distance swimmer was forced to abort her most recent attempt last September after potentially deadly jellyfish stings. An earlier attempt was meanwhile cut short by shoulder pain and an asthma attack.

According to her support team, Nyad was first stung on the neck just five hours into the journey, by the indigenous Olindias formosa jellyfish (aka Flower Hat Jelly) - not the more dangerous box jellyfish that ended her bid last year.

"She was treated with topical cream, remained calm and continues to swim," her support team reported.

That sting was then followed by three more, including one on her lips, AFP news agency reports.

To minimise the threat from the creatures, she now has a special head-to-toe swimming suit to wear at night.

She also has added jellyfish experts and detectors to her support team - alongside divers, whose task is to protect the swimmer from sharks, reports the BBC's Sarah Rainsford in Havana.

If that fails, a team of divers is on constant alert to plunge in and guide sharks away themselves, our correspondent says.

Before the swim, Nyad said she felt "excited" but that she was aware of the dangers.

"I respect this. I know how difficult it is. There's a reason no-one's ever done it. But I'm prepared."