Two dolphins spotted thrashing in shallow water sparked an emergency rescue.

The female common dolphins were stranded off Mumbles, Swansea, with one given first aid by marine mammal medics and moved to deeper water on 2 September.

The other managed to free itself.

"Following advice from our rescue coordinators and veterinary advisor, a carefully controlled refloat was authorised," the British Divers Marine Life Rescue (BDMLR) said.

Strandings happen when a marine animal becomes stuck in shallow water or on a shoreline. The often result in the animal's death or injury.

BDMLR said a call to its rescue hotline described "two dolphins stuck and thrashing in the shallows".

"One managed to refloat themselves independently and headed into deeper water, while the second was rolling and struggling to remain upright," it said.

"She was in good condition, had no visible injuries and responded well to the first aid provided."

The charity said that while bringing a stranded dolphin further onshore may seem counterintuitive, a stranded dolphin should never be pushed or dragged back out to sea.

"Dolphins may be exhausted, injured or unwell, and returning them to the water without an experienced assessment can put the animal at risk of drowning or stranding again," the charity said.

"Similar to how people can become disorientated at sea, dolphins need time and support to re-establish their balance once back in the water, part of the training our teams are trained to help them do."

BDMLR said the rescuers stabilised the dolphin in the water, supporting her weight while balance was regained.

Medics then withdrew their support, allowing the animal to float freely, trialling a release.

"The dolphin swam forwards, making a wide arc around the team before swimming strongly forwards in to deeper water," the charity said.

"Neither dolphin has been seen since, suggesting both have moved on away from the area."