She abruptly changed the rules as students sat for their KCSE exam on Thursday.
The CS gave a new edict to have all gates to examination centres remain wide open throughout the duration of the exam.
She further ordered all exam officials to refrain from taikng tea breaks and any other breaks in an effort to prevent any leaks.
CS Mohamed urged the invigilators and centre managers to only take breaks when the candidates are out of the exam rooms.
Persons of Interest
Unauthorised teachers will no longer be allowed within the exam centre compound, as well as, members of the public who have no role in the administering of exams.
The education boss has also ordered all police officers guarding exam materials not to leave them unattended at any point.
She explained that some of the security officials have been leaving exam papers in some rooms without anyone to monitor.
Amina further cautioned that failure to impliment the said rules will be treated as a crime.
"Failure to adhere to these guidelines and many other broad ones that have been already issued earlier on will lead to severe punishment," the CS warned.