KINSHASA (Reuters) - Congolese authorities have identified 10 more mass graves in a region where the military and militia fighters accuse each other of summary executions and burials.

The 10 new graves announced by the military on Monday bring to 52 the total number of such sites found in the Kasai region since the start of an insurrection last August by the Kamuina Nsapu militia which wants the withdrawal of military forces from the area.

Army prosecutor General Joseph Ponde told reporters in the capital Kinshasa that Kamuina Nsapu fighters were suspected of dumping bodies in the graves in Kasai province. The government also blamed the militia for mass graves discovered in neighboring Kasai-Central province.

But witnesses in Kasai-Central interviewed in March by Reuters said they had seen army trucks dumping bodies.

Bodies have not been exhumed from the newly found graves -discovered by Red Cross workers - and there are no estimates of the number of people buried in them.

More than 3,000 people have been killed in fighting between government forces and Kamuina Nsapu, according to the local Catholic church.

Another 1.3 million have fled their homes in an insurgency which poses the most serious threat to the rule of President Joseph Kabila who refused to step down at the end of his constitutional mandate in December.

The United Nations’ human rights chief last week accused a militia with links to the government of murdering and mutilating civilians in Kasai.

Congolese authorities deny those charges.

Last week, the U.N. Human Rights Council approved an international investigation into the violence, though Congolese authorities insist U.N. investigators will only be providing technical assistance.