Japan earthquake: 'Desperate measures' to cool reactors

There's increasing uncertainty about the radiation levels at the Fukushima nuclear power station in Japan, as what appears to be white smoke or steam, has been rising from the plant.

The authorities have been using a helicopter to try to douse the facility.

The plant - 220km (140 miles) north of Tokyo - was rocked by the first in a series of explosions on Saturday.

Meanwhile the aftershocks following Friday's massive earthquake continue.

The BBC's Chris Hogg reports.