Twelve students at Ichagaki Boys High School have been arrested after a dormitory was burnt.
The students were picked for interrogation after the school was closed on Wednesday following the mysterious fire.
The school Principal John Chege said the decision to send the students home was arrived at following a lengthy meeting with education and security officers.
Other schools where fire incidents have been reported are Murang’a, St Paul's Boys and Dr Kiano Boy High schools in Murang’a East and Kahuro sub-counties.
At St Paul's, two dormitories were burnt on Monday afternoon.
On Tuesday, secondary school principals were directed to immediately close schools if they suspect planned riots by students.
A meeting convened by Central Regional Director of Education Stephen Barongo and Murang’a County Commissioner John Elungata resolved that principals should send away rioting students to avoid destruction of property.
In Meru County, 30 students are being investigated after some schools were burned and property destroyed.
Commissioner Wilfred Nyagwanga said riotous students razed dormitories and destroyed school property.
At Thuura High School in Imenti North students burned all the dormitories.
At Meru School in North Imenti, students on Sunday evening held a peaceful protest, demanding that their colleagues sent home for lack of school fees be allowed back in school.
It emerged that the school had sent home a number of students who were being sponsored by well-wishers.
Efforts to get the principal's comments were fruitless.