Zambia's president tried to steady himself against his podium while watching a military procession but then he collapsed, a local newspaper reported on Monday.

Zambian President Edgar Lungu was delivering a speech to commemorate International Women's Day at Heroes Stadium in the capital Lusaka on Sunday when he felt ill. An aid managed to catch Lungu as he fell backward, The Post newspaper reported.

While musicians came on stage to perform before a shocked crowd, the president was carried away, The Post reported. A snap diagnosis said the president suffered from malaria and fatigue, according to a statement issued after the incident. But further medical tests on Monday ruled out malaria, which can be a deadly disease, said Amos Chanda, the president's assistant.

Lungu was admitted to the Maina Soko Military Hospital where observation showed that the president's blood sugar levels had dropped significantly, leading to his collapse, Chanda said in a statement.

The recently elected president has a history of a condition that narrows his esophagus, or food pipe, which led to his low sugar levels. The condition, known as achalasia, was first treated 30 years ago and has recently recurred, Chanda said.

Soon after being admitted to the hospital, Lungu assured his supporters that he was recovering well.

"There is nothing to worry about," President Lungu said in the statement.

Lungu became president in January this year, succeeding Michael Sata who died last year after a long illness. Rumors swirled about Sata's poor health for months when the late president was rarely seen in public. Sata reassured Zambians that he was fit to lead just weeks before he died.

The Zambian Medical Association commended Lungu's officials for their transparency about the new president's health.

"If he had just departed without any explanation, that would have fueled unnecessary speculation," said Aaron Mujajati, the association's president.

Lungu's office has released updates on his health, with journalists invited to visit Lungu while in hospital, The Post newspaper reported.