A fire killed 28 deaf children at a Russian boarding school on Thursday.

Teachers at the school in the Caspian Sea port of Makhachkala in southern Russia fought frantically to wake the children, aged between seven and 14, after the fire erupted at 2:30am.

"The children are deaf and they couldn't hear the noise," interior ministry spokeswoman Anzhela Martirosova said by telephone from Makhachkala.

"The teachers tried to wake the children up by shaking them, but it takes longer with a child with hearing difficulties. That was the biggest difficulty. It's a huge tragedy."

Twenty-nine other children were taken to hospital and four were in serious condition. One firefighter was also treated for burns.

The fire, the second at a Russian school this week, prompted Prime Minister Mikhail Kasyanov to order an immediate overhaul of safety measures.

On Monday, 22 children died in a fire at their wooden secondary school in a remote village in the Siberian region of Yakutia.

Schools and hospitals, particularly in rural Russia, have suffered from chronic under-funding since the collapse of the Soviet Union in 1991.

Firefighting equipment in schools is often kept in a poor state and electrical circuits are hazardous.

President Vladimir Putin sent a message to local officials in the mainly Muslim region reading: "All Russians are grieving. These were our children. It is our tragedy."

The spokeswoman, Martirosova, said most of the victims had probably died from smoke inhalation.

Officials linked the latest tragedy to strong winds that brought down power lines overnight and later hindered firefighting efforts.