The Rwandan army says it has arrested the brother of the former army chief of staff on charges of "destabilization."

Lieutenant Colonel Rugigana Ngabo is the brother of General Faustin Kayumba Nyamwasa, who was chief of staff until 2001 and went into exile in South Africa in February.

The army said Ngabo was arrested Friday arrest had nothing to do with his relationship to Nyamwasa.  Military officials said they are still investigating Ngabo's activities.

Nyamwasa is a leading critic of Rwandan President Paul Kagame.

The country's chief prosecutor accused Nyamwasa and the other officer of being involved in three grenade attacks in the capital, Kigali, in February. Two people were killed and 30 others were wounded.  He denies any involvement.  

Some information for this report provided by AFP.