A public square in Uganda's capital that is closed to the public is becoming a symbol for what many here see as the state's growing intolerance of political dissent.

Kampala's Constitution Square, once a cheerful place favored by politicians, is now protected by armed police with orders to arrest those who attempt to get in. Even the city's mayor has been advised to stay away.

Ugandan President Yoweri Museveni, who has held power since 1986, is accused by some of using state institutions such as the security forces to keep power.

Timothy Kalyegira, an independent researcher who is a well-known social critic in Uganda, said the square's closure highlights "the narrowing political space" in Uganda.

Police say such action is necessary to keep public order.