Scores of people are feared dead after a boat with 700 migrants on board capsized off the Libyan coast.

The L.E. Niamh is involved in the rescue mission, which has so far managed to save four hundred migrants from the sea.

25 bodies have also been recovered.

It's understood the boat capsized when migrants rushed to one side of the boat to be rescued, after the vesel got into difficulty this morning.

Melissa Fleming from the UN's Refugee Agency, the UNHCR, praised the efforts of the Defence Forces involved in the rescue:

Meanwhile, an online petition is calling for the Irish navy to be allowed continue its rescue missions of migrants.

The operations of the LE Niamh, the LE Eithne and other naval vessels in the Mediterranean are up for review in September.

Brian Killoran from the Immigrant Council of Ireland, says today's crisis off Libya shows the crucial humanitarian role being played by the Irish navy: