He had just returned home from an overseas absence that led to intense speculation about his health.
The world’s oldest head of state returned to Harare on Saturday morning after leaving a regional summit early on Tuesday.
The veteran leader said he had travelled to Dubai on a family matter.
“I had gone on a family matter to Dubai concerning one of my children,” he told reporters without giving details.
Flight data showed his plane went to Dubai after the original flight path had indicated a course toward Asia. Mugabe has received treatment in Singapore in the past.
His spokesman had denied reports that Mugabe, the target of near-daily protests in recent weeks, was ill.
He was expected to address a youth meeting at his ruling party’s headquarters later on Saturday.
His absence had raised the level of uncertainly in a country already in economic and political turmoil.
The Southern Daily website had posted an article headlined “Robert Mugabe suffers stroke, Mnangagwa now the new interim President of Zimbabwe”.
Emmerson Mnangagwa is the country’s vice-president.
Frustration has been rising in Zimbabwe over a plummeting economy and allegations of government corruption.
The country remains in political and economic turmoil, amid allegations of government corruption.
The capital saw a wave of protests last week, with dozens arrested.
Police on Thursday banned protests in the capital for two weeks, on the eve of a demonstration planned by a newly formed coalition of opposition groups.
Mr Mugabe has vowed to crack down on anti-government dissent.
Mugabe has been in power since 1980, and many in Zimbabwe have known no other leader in their lifetime.
He has said he will run again in elections scheduled for 2018.
Recently, his wife, Grace, said Mugabe would rule from the grave.