The Kenyan government says it is investigating dozens of primary and secondary schools over allegations that people are attempting to cheat in national exams.

Education Minister Amina Mohammed said cartels had been identified that were selling exam papers to parents and students ahead of tests later this month.

She said extra measures were being taken to safeguard the exams.

Exam cheating has been a serious issue in Kenya for some years.

Writing in Kenya's Star newspaper the East African education charity, Uweza, is calling for educational reforms saying children are under too much pressure to pass the exams at all costs including breaking the law.

Two years ago, the government banned schoolchildren from entering exam rooms with clipboards and geometry set boxes in a bid to curb cheating,