Twenty-three dolphins have died after becoming stranded on the Cornish coast.

An RNLI lifeboatman described Porth Creek near Portscatho as a "scene of carnage" after 21 dolphins died there. One was believed to be pregnant.

Rescuers helped seven at Porth Creek rejoin their pod out at sea but one was put down. Another dolphin was later stranded at Trellisick and put down.

The British Divers' Marine Life Rescue charity was responding to reports of more dolphins stranded along the coast.

It is thought a few dolphins may have got into trouble and their distress calls lured others into the inlet.

Helmsman Dave Nicoll, from Falmouth Lifeboat, said two of his crew got into the water with the dolphins.

He said earlier on Monday: "It's a horrible scene of carnage with bodies everywhere, but we are doing our best to help and will continue to support the expert groups."

Coastguards said the dolphins swam up the Percuil River and were beached in Porth Creek on Monday morning.

A team from the Divers' charity worked with vets and coastguards to rescue seven of the stranded mammals. Another animal had to be put down.

Charity spokesman Tony Woodley said this was the biggest mass stranding of marine life in the UK for many years.

"We haven't seen a stranding anywhere near this scale since 1981 when pilot whales were beached on the east coast.

"This is extremely rare."

He said the animals were striped dolphins - an ocean-going, rather than coastal breed.

One theory is that a few of the animals may have followed fish, which were feeding on a large algae bloom, into the river mouth.

It is believed their distress cries may have lured other members of their pod to the creek.

The carcasses of the dead animals were removed from the creek and logged by volunteers from Cornwall Wildlife Trust before being taken away for post-mortem examination.