Japan says it is stepping up efforts to cool reactors at the tsunami-stricken Fukushima Daiichi nuclear plant. Army helicopters dumped tonnes of water to try to prevent a meltdown of fuel rods. Water cannon will join the operation shortly and it is hoped electricity will be restored soon. Meanwhile, the confirmed death toll from Friday's 9.0 magnitude quake, which triggered a tsunami, has risen above 5,000. Police say 5,178 are confirmed dead and another 8,606 people are still missing.