At least three students have been injured after a fire broke out at a girls boarding school in central Kenya's Isiolo town on Saturday, the Red Cross says.

It comes after the deaths of at least 21 children in a fire at a boarding school in Nyeri, also in central Kenya, at around 23:00 local time (20:00 GMT) on Thursday.

A Kenyan police spokesperson said the blaze destroyed dormitories at Isiolo Girls High School, before being contained.

The cause of the blaze is unknown, but there have been numerous fires in boarding schools in Kenya in recent years, prompting national concern about safety standards.

The Kenya Red Cross said three children had suffered minor injuries, and had received psychological first aid.

Police, fire and rescue squads could be seen using flashlights to search for any students and salvageable property in the destroyed dormitories, Reuters news agency reports.

Meanwhile, DNA testing will begin on Monday to identify the bodies of children who died in the fire at Hillside Endarasha Academy on Thursday night.

Officials say 17 children remain unaccounted for - with some parents and relatives camping at the school to demand answers.

President William Ruto has declared three days of mourning, starting on Monday, for the victims of the fire.

The cause of the fire is still unclear.

Investigators should "assess whether or not the tragedy may have resulted from negligence and/or recklessness", the chief prosecutor said in a statement.

Director of Public Prosecutions Renson Ingonga said the tragedy "evokes bad memories of other similar school fire incidents" that many times pointed to a failure to comply with safety standards.

In 2022, a dormitory in western Kenya burnt down, with several students later arrested on suspicion of arson.

In 2017, 10 students died in an arson attack at Moi Girls High School in the capital Nairobi.

At least 67 students died in Machakos County, south-east of Nairobi, in the deadliest Kenyan school arson that took place more than 20 years ago.