Fidel Castro has fallen during a live televised speech before a rally of tens of thousands of people.
He was back standing before the crowd a few minutes later.
Cuba's leader was speaking in Havana when suddenly his body could be seen listing off to the side before the government cameras pulled away and concentrated on the crowd.
"Calmness and courage, we lift our flag," foreign minister Felipe Perez Roque said, taking the microphone immediately after 74-year-old Castro appeared to faint.
"Companero Fidel obviously has had in the middle of the heat ... a momentary fall," Perez Roque said.
Less than 10 minutes later, Castro was back behind the podium, asking the crowd not to worry, saying he was merely tired and would return in the evening to finish his speech.
"Let me rest, sleep a few hours," Castro told the crowd. "Last night I did not sleep at all. I am fine. We will see you tonight."