Sirens wailed and people bowed their heads and wept along Japan’s devastated north-east coast today as they marked a month since the devastating tsunami which killed up to 25,000 people and unleashed a nuclear crisis.

Japanese police are racing to find thousands of missing bodies before they completely decompose along a stretch of tsunami-devastated coast that has been largely off-limits because of a radiation-leaking nuclear plant.

Setbacks mounted in Japan’s nuclear crisis today, with nearby seawater showing the highest radiation levels yet and the president of the wrecked plant being taken to hospital with stress.