Updated

Two top Greek police chiefs quit in a shake-up on Monday after the murder of an anti-fascist musician by an alleged member of neo-Nazi party Golden Dawn sparked protests, and led to a probe of a possible police connection.

Police said two regional supervisors for southern and central Greece had stepped down as an inquiry was under way into possible links between the police department and Golden Dawn.

The police shake-up also involved the suspension of a number of senior officers on the island of Evia for failing to investigate a Golden Dawn office near a local police station where weapons were allegedly kept.

The department's internal affairs division was also tasked with determining whether officers had participated in illegal Golden Dawn activities.

Around 30 such incidents are under investigation, a police source said.

At the same time, nearly a dozen senior officers switched posts, including the heads of the anti-terrorist squad, the organised crime squad and the guns and explosives squad, police said.

The fatal stabbing of 34-year-old hip hop artist Pavlos Fyssas on September 18 touched off street protests and prompted authorities to take a harder stance against Golden Dawn.

The neo-Nazi party has already been linked to assaults on immigrants although it officially denies such attacks, while several of its lawmakers have also been involved in violent incidents and have yet to face justice.

Three Golden Dawn lawmakers are to be tried for smashing up the street stalls of migrant peddlers in two separate incident.

Another member of parliament, party spokesman Ilias Kasidiaris, is also due in the dock for striking a female Communist MP during a talk show last year.

'Rank-and-file officers'

Observers however voiced scepticism about the scope of the police shake-up.

"There is an outcry and that is why they are doing this," Sophia Vidali, a criminologist at the University of Thrace, told AFP.

She added that it was "not about the senior officers alone, we know there is an issue with the rank-and-file officers, entire stations might have to change," she said.

Migrant groups have repeatedly complained of police apathy when reporting racist beatings. And in many cases, the victims of the attacks claim to have been threatened with deportation by police.

Capitalising on a rise in social tension in the debt-stricken country, Golden Dawn was first elected to parliament last year with nearly seven percent of the vote, winning 18 seats out of an overall 300.

It further boosted its popularity by organising food handouts and blood donations exclusively for Greeks.

In recent days, media have quoted alleged insiders saying that the group had recently branched out into selling protection to migrant peddlers and nightclubs.

The government is now trying to find a way to deal with the neo-Nazi party, which so far has benefitted from a law granting elected MPs immunity from prosecution.

Golden Dawn's popularity has appeared to suffer a blow following Fyssas's murder.

A Monday poll in pro-government daily Eleftheros Typos showed its approval ratings had dropped to 5.8 percent, compared with 8.3 percent before last week's murder.

Prior to the killing, various polls indicated that Golden Dawn's popularity had climbed as high as 13 percent. Even now it remains the country's third most popular party.

The musician's killer, 45-year-old truck driver George Roupakias, has confessed to the crime but claims he was acting in self-defence.

He has been charged with voluntary manslaughter and illegal possession of a weapon.

Fyssas, who wrote music under the nickname Killah P, was fatally stabbed outside a cafe in the working-class Athens district of Keratsini.

Golden Dawn quickly denied links with the alleged killer, but pictures soon surfaced of Roupakias participating in party activities and members of his family reportedly worked for the organisation.