The men, aged 39 and 55, were picked up by officers from Scotland Yard's counter terrorism command.
Both are being held under the Extradition Act after being arrested at a residential address in west London.
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Mother of Connor Sparrowhawk, who died under the care of an NHS Trust, called "vindictive cow" in voicemail allegedly sent by trust worker.
Another beautiful day for many of us with blue skies.