At least 21 dolphins have died after becoming stranded in a river in Cornwall.

  Dead dolphins on the river bank

A rescue operation was launched after a pod of around 15 striped dolphins swam up the Percuil River near Falmouth, Cornwall, before they were beached in Porth Creek.

More dolphins - alerted by their distress calls - then followed and also became stuck.

Rescuers led by British Divers Marine Life Rescue (BDMLR) saved seven of the stranded animals and the last two were taken out to deep water in stretchers attached to boats.

The coastguard said by the time the boats left a pod of up to 60 dolphins were following them.