A fire in a school dormitory in Kenya killed 18 students and seriously burned 13 others, police said on Friday.

There are fears that the death toll may rise, police said.

The cause of the fire on Thursday night at Hillside Endarasha Primary in Nyeri county was being investigated, police spokesperson Resila Onyango said. The school caters to children up to the age of 14.

Nyeri County Commissioner Pius Murugu and the education ministry reported that the dormitory that caught fire housed more than 150 boys. Since most of the buildings are built with wood, the fire spread very fast.

The school, which has 824 students, is located in the country’s central highlands, 200 km north of the capital, Nairobi, where wooden structures are common. Anxious parents who had been unable to trace their children among survivors waited at the school, engulfed with grief.

President William Ruto called the news “devastating”.

“I instruct relevant authorities to thoroughly investigate this horrific incident.”