Japan is extending the evacuation zone around the Fukushima nuclear plant because of increased radiation.
The news comes as ceremonies have been held to commemorate one month since the earthquake and tsunami devastated the country’s north-east coast.
Survivors now living in shelters because their homes were destroyed observed a minute’s silence, marking the moment the quake struck.
Japan’s prime minister Naoto Kan has thanked people around the world for their support and solidarity.
The government says it is expanding the evacuation zone around Fukushima beyond the current 20 kilometre radius to include areas where higher radiation has been detected. One village affected is 40 kilometres from the plant.
A senior nuclear safety official has apologised for the worry and inconvenience caused by the radiation spill.
The disasters have left nearly 28,000 people dead or missing. Another 150,000 are homeless.
Many people have been returning to houses that are still standing to collect belongings, before demolition workers move in.
One group of workers in Kesennuma, among the worst-hit cities in Miyagi prefecture, had a special mission to carry out for an old woman – to salvage a chest-of-drawers that was her wedding present decades ago.