Demonstrators brandishing Molotov cocktails, fireworks and clubs have taken to the streets of Athens.
Security forces are holding them back in some areas of the city with water cannon and shields.
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Canada, Mexico, Australia, Argentina, Brazil, South Korea will also be free from the levies announced by Donald Trump.
Bolton is viewed with contempt by almost the entire foreign policy establishment in Washington.
A top temperature today of 13 Celsius (55F).