BBC News with Nick Kelly

The Hungarian government says it will take more than a year and cost tens of millions of dollars to clear up the damage caused by toxic sludge, which burst from a reservoir. Four people were killed and more than 100 injured after the mud from an industrial plant engulfed villages near the town of Ajkai. The Hungarian Environment Minister Zoltan Illes told the BBC that the spill covered an area 20km long by 10km wide. Mr Illes described the scale of the disaster.

"Unfortunately, never happened on this planet earth a similar accident of this magnitude and this size caused by red mud. So according to our estimation, minimum one and half years is needed and a really vast amount of money to clean up the area."