The Ukrainian authorities have doubled the number of firefighters to fight forest fires at the partially exploded Chernobyl nuclear power plant in 1986.

Some 1,400 sprayers are now trying to control the smouldering fires. Strong wind complicates the approach.

An international organization of activist doctors, meanwhile, warns not to make the danger smaller than it is.

According to these doctors, there are radioactive clouds over Ukraine that can also blow to other European countries.

It is true that the radiation is not yet significant, but that can happen if areas burn that was more polluted during the nuclear disaster.

The Ukrainian capital Kiev, among others, is very much affected by the smoke from the fires, some seventy kilometres away.

According to the authorities, there is no question of radioactivity. However, it does warn about health problems from the smoke.