Authorities say arsonists have firebombed an Athens office of a far-right, anti-immigrant party, a day after the suspected racist murder of an Iraqi man in the Greek capital.

The fire brigade says nobody was hurt in Monday's attack on the Golden Dawn facility in the central Pangrati area. The assailants escaped arrest.

The party, which rejects the neo-Nazi label, won 18 of the Greek Parliament's 300 seats in June elections by running on an anti-immigration, nationalist platform.

Debt-crippled Greece is the European Union's main entry point for illegal immigrants.

The government has sought to blunt Golden Dawn's rising influence by placing illegal immigrants in detention camps pending their deportation.

The party's ascendance has been coupled with growing reports of attacks on immigrants. The Iraqi's attackers remain at large and unidentified.