Two officers in Rwanda's military have pleaded not guilty to charges of inciting insurrection against the government.

Brig. Gen. Frank Rusagara and Col. Tom Byabagamba, who were arrested in August 2014, appeared before a military tribunal in Kigali on Tuesday to answer charges of inciting insurrection among citizens, engaging in activities aimed at tarnishing the name of the country, its leadership and illegal possession firearms.

Byabagamba, who once was the commander of the elite presidential security force, is a brother to the prominent Rwandan exile and presidential critic, David Himbara. Rusagara retired from the army in 2013 and is brother in-law to Himbara and Byabagamba.

Many senior army officers have fallen out with President Paul Kagame, with some fleeing into exile because they believed their lives had been threatened.