Coastguards have warned people about jumping off cliffs in a practice known as "tombstoning" after a 75-year-old man was injured by diving 30ft (9m).

Portland Coastguard was called to Durdle Door at 1504 BST on Sunday after the swimmer got into difficulties.

It is believed the Dorset man, who had jumped from the cliff before, had landed badly in the water.

He was later taken to hospital with severe abdominal pains after being rescued by helicopter.

'Hurt in past'

A coastguard spokesman said: "What was being done here was tombstoning, jumping from rocks.

To find somebody of 75 doing it, I just find completely unbelievable James Weld, Lulworth Estate

"It's dangerous. You don't know the depth of the water. So many people have been hurt in the past from tombstoning."

The pensioner was understood to be diving into the sea from the Jurassic Coast World Heritage landmark with other members of his family.

James Weld, of the Lulworth Estate which owns the beauty spot, said people continued to take part in the dangerous activity despite a number of signs warning people not to climb the cliffs.

"It's actually a very, very stupid thing to do because there are a lot of rocks under the water, which we and the coastguards try to tell people frequently," he said.

"To find somebody of 75 doing it, I just find completely unbelievable.

"The hard limestone reef along the coast means there are a lot of rocks just under the water."