France has opened investigations into former Democratic Republic of Congo rebel leader Roger Lumbala.

He is accused of "complicity in crimes against humanity" for his actions during Congo's civil war in 2002.

The investigation was announced on Monday after Mr Lumbala's arrest on Saturday.

His charges are over actions predominantly against the Nande and Twa ethnic groups in northeastern Ituri region, AFP news agency reports.

The United Nations had in 2003 accused Mr Lumbala's party, the Congolese Rally for Democracy-National (RCD-N), of human rights abuse.

Mr Lumbala is a former opposition MP.