A 45-year-old man arrested over the alleged stabbing of an anti-fascist activist has admitted being a follower of Greece's far-right group Golden Dawn, according to media reports.
Golden Dawn has condemned the killing and denied having any involvement, accusing people of using the "tragic event" for political ends.
The far-right party, which has 18 MPs in the Greek parliament, has repeatedly been accused of violence towards its political opponents.
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The man, in his thirties, was found with stab injuries on the upper deck of a bus in Handsworth, Birmingham, on Monday night.