Three emergency workers have been exposed to dangerous levels of radiation at the Fukushima nuclear plant, according to the Japanese Nuclear Safety Agency

Two have been hospitalised in what the government has described as a 'very regrettable situation' at the Daiichi nuclear plant's reactor No 3.

The workers were hospitalised 'after being exposed to radiation ranging from 170 to 180 millisieverts', NISA spokesman Hideyuki Nishiyama said.

They were working in a building where the turbine is located.

An exposure of 100 millisieverts per year is considered the lowest level at which any increase in cancer risk is evident.

Meanwhile, radioactive iodine levels in Tokyo's tap water are reported to have fallen below the safe limit for infants but some areas are reporting problems with their supplies.

Despite this, stores in Tokyo are fast running out of bottled water.

'Customers ask us for water. But there's nothing we can do,' said Masayoshi Kasahara, a store clerk at a supermarket in a residential area of eastern Tokyo.

'We are asking for more deliveries but we don't know when the next shipment will come.'

This morning, Japan's chief cabinet secretary moved to reassure the public that the initial water warning was based on conservative standards.

Authorities in Tokyo say they will distribute almost 250,000 bottles of water to families with children under the age of one.

Radiation above safety levels has also been found in milk and vegetables from Fukushima, where the stricken nuclear plant is located.

IFA expresses sympathy

Irish Farmers' Association President John Bryan has spoken to Japanese Ambassador to Ireland Toshinao Urabe and written to him on behalf of the Irish farming community expressing sympathy to the Japanese people following the devastation caused by the recent earthquake and tsunami.

Mr Bryan said the scale of the destruction meant a significant number of farm families along the coastline in the northeast of the country would have been badly affected.

For many years, IFA has enjoyed close working relations with the Japanese farm organisation, Ja-Senchu, in relation to the World Trade Organisation trade negotiations and a delegation visited Ireland for bilateral talks in 2009 on the issue.