Updated

Two senior Ugandan police officers have been charged over the mysterious kidnapping of a Rwandan refugee who had been a member of his country's presidential guard.

Officers Joel Aguma and Nixon Karuhanga appeared before a military court-martial Friday in Kampala.

Aguma leads the police's standards unit and Karuhanga once led a special operations unit.

Joel Mutabazi was a member of Rwanda's presidential guard before he fled to Uganda, where he won refugee status.

In 2013 he was repatriated to Rwanda, where he is serving a life term after being convicted of plotting against the government.

It is not clear why the two police officers are being charged now, although Uganda's president urged a purge of "criminal" officers after the murder in March of a senior policeman.