Russia's worst woodland and peat bog fires in decades have been raging for days following the hottest summer in 130 years. Thousands of soldiers are assisting efforts to put out the blazes - so far to little avail.
The situation is particularly bad in the Nizhny Novgorod region, around 400km east of Moscow, home to the Sarov nuclear research centre. After the number of those fighting the flames around Sarov had been increased to 2 000, the situation had eased, Stepanov said.
The official number of people killed in the fires has now reached 48. But the German-based relief organisation Caritas International, which has begun to distribute clothing and food to the fires' victims, says more people have likely died than is known.
On Wednesday, there were reports of the destruction of cultural heritage for the first time.
A Russian Orthodox Church made of wood in the village of Yevlashevo, in the Penza region, was destroyed in the fires. Some of the statues inside dated from the nineteenth century.
The situation in the capital Moscow, home to 10 million people, was also worsening, as smoke from peat bog fires continued to cover the city in smog.
"We're preparing ourselves for a worst case scenario," said Civil Defence Minister Sergey Shoigu.
Forecasts have predicted that temperatures in the capital will increase to around 40C. Many people have complained of breathing difficulties, allergies, nausea and headaches.
Many birds, especially exotic species such as parrots and cockatoos were dying as a result of the smog, the daily Moskovsky Komsomolev wrote, citing veterinary surgeons.
The director of the Moscow bird clinic, Vladimir Romanov, said that pet owners were bringing in dozens of unconscious birds. Some of them had burst blood vessels and signs of severe carbon monoxide poisoning.
May birds were simply falling dead from the sky because of the lack of oxygen in the air and poisonous substances in the atmosphere released by the fires, Komsomolev wrote.