Kigali - Rwandan President Paul Kagame has fired his justice minister and replaced her with a high court judge, state radio said on Friday.

Edda Mukabagwiza had been head of the justice ministry for nearly three years. State-owned Radio Rwanda said Kagame did not give an immediate reason for firing her.

"With effect from today, Edda Mukabagwiza has been relieved of her duties as the minister of justice," Radio Rwanda said.

It added that Tharcisse Karugarama, from Rwanda's High Court had been appointed as the new justice minister.

Rwanda's justice system has been criticised for failing to speed up the trials of perpetrators of the 1994 genocide in which some 800 000 minority Tutsis and moderate Hutus were butchered in 100 days of killings.

The country's prisons are overflowing with thousands of suspects linked to the genocide, many of whom have been in prison for nearly 10 years without facing justice.

Rwanda introduced the traditional village "gacaca" courts, partly to speed up trials but the courts have also come in for criticism which says they lack basic judicial standards.

Local media said failing to clean up a backlog of cases could have been one of the reasons for Mukabagwiza's dismissal.

In the last year, Kagame has sacked several ministers for embezzling state funds. But rights bodies have accused him for suppressing political space and limiting free speech.