Uganda's leading independent media group said it is under a "military siege" after the army chief ordered the shutdown of its newspapers, TV station, and radio outlets.

NTV Uganda and Spark TV were forced off air after armed soldiers surrounded the Nation Media Group (NMG) Kampala offices on Sunday.

The stations went off air in the early hours of Sunday, with local media reporting that the broadcasts displayed the message: "Video unavailable".

Headquartered in Kenya, NMG is East Africa's largest independent media company, and in Uganda also owns the influential Daily Monitor, The East African, and other platforms.

The news came after the head of Uganda's military, Muhoozi Kainerugaba, announced on social media that they would cease operations immediately.