Greek police have arrested the leader of the far-right Golden Dawn party, Nikolaos Mihaloliakos, on charges of forming a criminal organisation.
Four more Golden Dawn MPs, a leader in an Athens suburb and nine other party members have also been arrested.
The arrests come amid anger over the murder on 18 September of anti-racist musician, Pavlos Fyssas.
A man held for the stabbing told police he was a Golden Dawn supporter, though the party strongly denies any link.
One of the MPs arrested on Saturday was party spokesman Ilias Kasidiaris.
Golden Dawn has called on its supporters to rally outside the police headquarters in Athens and has vowed to fight back.
