A prominent opposition figure in Uganda who is on trial in a military tribunal has begun a hunger strike, his wife said, two weeks after the country's top court banned courts-martial from trying civilians.

A prominent opposition figure jailed in Uganda for allegedly threatening state security is unwell and in need of urgent medical care.

Detained Ugandan opposition politician Kizza Besigye has begun a hunger strike as his time spent in detention awaiting trial nears three months.Besigye, 68, was charged in a military court with possession of pistols and attempting to purchase weapons abroad - accusations which he denies.