Eight students alleged to have been involved in a suspected arson attack at a Kenyan girls' school that killed 16 pupils have been arrested, police say.

The fire in the early hours of Thursday morning at the Utumishi Girls Academy in Gilgil, about 120km (77 miles) north-west of capital city Nairobi, tore through the upper floor of a dormitory which had 135 bunk beds.

After interviews with students and staff and a forensic review of CCTV footage, eight pupils at the school were identified as "persons of interest in connection with the planning and execution" of the fire, the National Police Service said in a statement.

Investigations are continuing into the exact cause of the blaze.

Police said the students were detained for questioning after being traced to their homes and brought back to the school, while others who had remained in the area were also tracked down and detained.

The eight were among 30 students who were initially traced and recalled back to the school by detectives investigating the deadly fire.

As investigators continue their work, sorrowful scenes unfolded at the school as parents and relatives broke down while waiting for updates about their loved ones. Security was heightened around the institution as crowds gathered demanding swift action and accountability over the incident.

"I arrived at the school at 07:00 and three hours later I don't have any information," Njuki Nthimba, who is looking for his niece, told the BBC on Friday morning.

"Some officers came from the school and asked the parents to group themselves in three groups. Group one is for parents whose children have been arrested in relation to the incident, group two is parents whose children died, and group three is parents who don't know where their children are.

"I handed them my niece's name, and I am now waiting to be told information about her."

Samuel Githua came to the school to look for his sister.

"I don't know where my sister is, we've been told some children are in hospital, some in the mortuary... Our mother died when we were young, so I have taken care of her like a father and mother. She has been my child," he added.

Kenya has had a long history of school fires - just two years ago at least 21 people died in a dormitory fire in central Kenya.

Many fires reported in boarding schools have been the result of arson, with disgruntled pupils - angry about the discipline and living conditions - accused of being responsible, while others were caused by accident.

Overcrowding in dormitories and the failure to follow safety guidelines, such as keeping exits clear and windows unlocked, have frequently been blamed for the high number of casualties.