The International Criminal Court building is seen in The Hague, Netherlands, Jan 16, 2019. REUTERS/Piroschka van de Wouw

Burkina Faso, Mali and Niger have initiated a year-long process of withdrawing from the International Criminal Court (ICC), the court said in a statement.

The military-led West African countries announced in September their withdrawal from the ICC, denouncing it as "a tool of neocolonial repression".

All three are fighting Islamist insurgencies that have seized large areas of territory and stepped up attacks on military targets this year. Rights groups have accused militants as well as the armed forces of Burkina Faso and Mali of possible atrocities.

The court is the world's permanent war crimes tribunal, which prosecutes individuals accused of genocide, crimes against humanity, war crimes and the crime of aggression when national courts are unwilling or unable to act.