Zimbabwean officials have dismissed speculation about President Robert Mugabe's health after the elderly leader stumbled in public.

Presidential spokesman George Charamba was quoted in the state-run Herald newspaper Saturday as saying that the 91-year-old leader's struggle to climb a ramp was a "very minor incident." He said Mugabe, who has ruled Zimbabwe since 1980, is in good health.

Mugabe stumbled as he made his way to the podium at the India-Africa Summit this week. Online videos show Indian Prime Minister Narendra Modi offering Mugabe a hand as he regained balance.

Opposition spokesman Obert Gutu said it is a sign that Mugabe is too old to rule.

Earlier this year Mugabe tripped and fell at the Harare International Airport in Zimbabwe. In September he read the wrong speech in parliament.