Two former commandos and a Kavala municipal employee are the suspected brains behind a criminal organization that is believed to have carried out numerous armed robberies on banks and petrol stations in northern Greece.

Authorities arrested 23 people, aged 24-50, in a large-scale operation on Sunday night in connection to the robberies, the last two of which are thought to have netted the gang at least 450,000 euros.

Investigators believe that the masterminds of the operation have ties to the extreme right wing.

One of the suspects allegedly made specific reference to the ultranationalist Golden Dawn party in a telephone conversation taped two days before the gang allegedly hit two banks in Serres Kavala in June, during which they also shot at police.

Golden Dawn denied any connection to the suspect on Monday.

The 23 suspects arrested are also being investigated for smuggling illegal firearms, selling protection and dealing in narcotics.