Uganda president under pressure to release opposition leader

Uganda's president has defended the arrest of the country's main opposition leader ahead of next year's presidential election.

Kizza Besigye has been arrested on treason charges, but his supporters claim the charges are politically motivated.

The issue is threatening to overshadow the Commonwealth conference being held in Malta this weekend with the president, Yoweri Museveni, under pressure to release him.

British Prime Minister Tony Blair has said that the detention is causing a great deal of concern.