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.

An expert says on average, a person can survive three weeks without food if they consume fluids, three days without both food and water, and only three minutes without oxygen

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.