A British woman has been attacked by a shark while snorkelling near a remote island in the South Atlantic.

She was in English Bay off Ascension Island, part of St Helena, and a source told the Times her husband punched the shark to scare it away.

The woman, who works for the St Helena government, was treated in hospital locally.

St Helena is a British Overseas Territory, 1,150 miles (1,850km) off the west coast of Africa.

The government has warned swimmers entering the water in the area that they do so at their own risk.

It said the incident was reported to them on Friday at 4pm local time (17:00 BST).

The far-flung islands of St Helena, Ascension Island and Tristan da Cunha lie midway between Africa and South America and, though far from each other, they form a single territorial grouping under the sovereignty of the British Crown.

In the 1600s, the English East India Company was given a Royal Charter which allowed it to colonise the island, but St Helena is perhaps best known as the destination to which Napoleon Bonaparte was exiled in 1815 after his defeat at the Battle of Waterloo.

Today, the islands have a combined population of less than 6,000.

St Helena and Ascension Island are linked to the outside world by a Royal Mail Ship, the St Helena, which had been making the five-day journey from South Africa, every three weeks, but is currently out of action for repairs.