Bathers on the west coast have been warned to exercise caution on beaches after an infestation of deadly Portuguese man o’war jellyfish.

According to today’s Irish Independent Irish Water Safety has warned that the jellyfish have been arriving at coastal zones in the west, northwest and south.

The jellyfish have been known to kill people such is the severity of their sting.

Sightings of the jellyfish have been reported in Mayo, Galway, Donegal, Cork, Kerry and Clare.

According to Irish Water Safety more than 20 have been spotted around Keel Bay in Achill.

If stung, bathers are being advised not to rub the affected area and to use gloves or a towel while removing any attached tentacles.

The sting can cause anaphylactic shock, with anyone stung also advised to seek medical attention if they are feeling anything other than minor discomfort.