The Americas have seen the sharpest rise in swine flu deaths
The number of swine flu deaths reported worldwide has jumped by more than 700 in a week, latest World Health Organization figures reveal.
More than 5,700 swine flu deaths were reported by 25 October, compared to nearly 5,000 the week before.
The biggest rise was in the Americas where 4,175 deaths have been reported, up 636 from the week before.
Meanwhile, Ukraine has shut all schools and banned public meetings for three weeks after its first swine flu death.
Prime Minister Yulia Tymoshenko said the measures were to prevent the spread of the H1N1 virus.
Mrs Tymoshenko said there would also be restrictions on what she called non-urgent travel between different parts of Ukraine.
The latest WHO figures showed there had been 440,000 confirmed cases of the H1N1 virus worldwide.
But the organisation said that as many countries have stopped counting individual cases, the actual number is likely to be significantly higher.
The BBC's Imogen Foulkes says the WHO has warned for months that as winter sets in, the northern hemisphere can expect swine flu cases to rise. Now that appears to be happening.
The virus emerged in Mexico in April and was declared a global flu pandemic on 11 June.
"In the temperate zone of the northern hemisphere, influenza transmission continues to intensify, marking an unusually early start to winter influenza season in some countries," said the WHO's latest update.
Statistics showed fatal cases in Europe climbed to at least 281, while those in Asia-Pacific rose to 1,070.
In a separate statement, the WHO said that experts meeting this week had concluded that a single dose of swine flu vaccine was sufficient to immunise adults and children over 10.
The Strategic Advisory Group of Experts (Sage) said that countries that had made vaccinating children a priority could administer them a single dose to ensure that as many as possible are immunised quickly.
It said that while more data on children between six months and 10 years was needed "the priority should be to give them at least one dose of vaccine now, and to cover as many of them as possible".