Outside The Shard, crowds gathered and commuters stopped to take pictures of the protesters as they progressed several hundred feet up.
The women are climbing in two groups - three in each.
They are currently about halfway up and appear to have stopped for a break.
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The Duke of Cambridge said his children were beginning a "lifetime of friendship" with Canada as they began their tour of the country.
When and where are they on, and how do they work?
What better, more dramatic spectacle has there ever been on American television?