Two people were killed in a drive-by shooting outside the offices of Greece's far-right Golden Dawn party in Athens today, police have said.

The attack took place as the government is cracking down on Golden Dawn, Greece's third-most popular political force.

A party sympathiser stabbed an anti-fascism rapper to death in September.

The victims were aged 20 and 23 years old, Golden Dawn said on its website.

Police have not yet verified their identities and details on the shooting were not immediately available.

A third person was seriously wounded and taken to hospital.

"The murderers - whoever they are - will be dealt with unsparingly by our democracy. Let everyone know this," government spokesman Simos Kedikoglou told reporters outside the prime minister's mansion.

Scores of police in riot gear cordoned off the streets surrounding the offices.

The offices are located in the northern Athens suburb of Neo Iraklio.

TV footage showed Ourania Mihaloliakou, the daughter of the party's detained leader, had rushed to the scene.