A British army helicopter has been called in as part of an emergency operation to reach farms and families still cut off by snow drifts in Northern Ireland.

Thousands of animals have been buried in the snow with some farmers saying their livelihoods have been lost as a result.

The helicopter is being used to airlift fodder and provisions to farmers, who are now bracing themselves for more snow expected later this week.

Agencies involved in the severe weather response are warning hill walkers of hazards, such as cornices and avalanche risks, in areas affected by snow and strong winds.

All walkers are being urged to consider the potential risks before embarking on any walks in those areas.

Motorists are asked to continue restricting their journeys to those that are absolutely necessary in affected areas.

Meanwhile, Met Éireann has issued a weather warning for most of the country, and has forecast sub-zero temperatures overnight.

The snow-ice warning covers Munster, Connacht, Leinster, Cavan and Monaghan.

Light snow showers and icy stretches on roads can be expected until at least 6am tomorrow.

Temperatures tonight are forecast to fall to between zero and -3C in some areas.

Tomorrow is also expected to be bitterly cold, with sleet and snow showers.

The cold weather is expected to continue for several days.

Met Éireann expects that over the Easter weekend outbreaks of rain, sleet and snow will become more widespread from the southwest.