Video report by ITV News Correspondent Dan Rivers
German Chancellor Angela Merkel has been seen shaking at a public event for the third time in less than a month.
Mrs Merkel’s body shook visibly as she stood at a military honours ceremony alongside the Finnish prime minister Antti Rinne in Berlin.
As the national anthems played, Mrs Merkel's hands were seen to grip into fists and her mouth set in a determined, thin expression.
The visible shaking followed similar episodes on June 18 and June 27.
As in both those cases, the 64-year-old recovered quickly as she started walking.
"I am fine," she told reporters after her meeting with Mr Rinne.
She added: "I will have to live with it for a while now, but I am very well and people don't have to be worried."
When pressed again on the health concerns, Mrs Merkel said: "My comments on this are done today, and I think my statement that I am fine can find acceptance.
"I said that I have to process this event and that I am in this process, and I think that just as it came, it will go away one day.
"I am very firmly convinced that I am entirely capable of performing."
A professor explains what could explain her shaking
Professor Leslie Findley, a neurologist, told ITV News there could be two explanations for her shaking.
He said: "I think there are two common possibilities, though it is guesswork.
"The first is that it is an essential tremor or the second possibility is this could be a form of Tremulous Parkinson's Disease. Either way, it would not interfere with her ability to carry out her work."
The first incident happened in hot weather, and Mrs Merkel said afterwards that she was fine after drinking three glasses of water.
The weather was cool at the latest event.
Mrs Merkel said as she attended the G20 summit in Japan on June 29 that she understands questions surrounding her health, but insisted: “I’m fine.”