"Yes, I was dead. It's true I was dead. I resurrected as I always do once I get back to my country. I am real again," the 92-year-old ruler told reporters at Harare international airport after arriving from Dubai.
His comments came after an online news site reported he had died mid-air on his trip to Dubai.
Mugabe's health has been increasingly under the spotlight in recent years, particularly after he fell down a staircase after addressing supporters last year.
Zimbabwe police announced on Thursday a two-week ban on protests in the capital Harare, after a string of violent demonstrations in recent weeks calling on Mugabe to step down.
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In a speech later today Mugabe said his government would not allow violent demonstrations by opposition political parties against his rule.
"We can't allow them to continue on these violent demonstrations unimpeded. No, enough is enough," Mugabe said in an hour-long speech to the youth league of his ruling ZANU-PF party.
They are pursuing their selfish agenda that targets the undemocratic removal of an elected government from office," he added.
Mugabe also accused the West of helping to finance the opposition.
"Our enemies use money and opposition parties to provoke internal instability and conflicts," he said.
Zimbabwe has suffered an economic crisis since the start of the century, with 90 percent of the population not in formal employment.
The cash-strapped government has been slow to pay the salaries of public sector workers while banks are running out of cash.