President Sata, who was being treated in the UK, died in London's King Edward VII hospital on Tuesday night.
Media said that he died after "a sudden onset [of] heightened heart rate".
It is not immediately clear who will succeed the president. The issue may be decided by the Zambian cabinet which meets on Wednesday morning.
"It is with a heavy heart that I announce the passing on of our beloved president," cabinet secretary Roland Msiska said on national TV.
He said that Mr Sata's wife and son were at his bedside.
"I urge all of you to remain calm, united and peaceful during this very difficult period," Mr Msiska added.
0 comments: