Graphic: Jamie Brown

Graphic: Jamie Brown

Three men and a woman have been arrested following a series of police raids in Melbourne’s south-eastern suburbs focusing on the Comanchero bikie gang and a gym nearly blown up by the club’s rivals.

Victoria’s anti-bike Echo taskforce searched the Nitro Gym in Hallam on Friday morning, while officers raided six other locations in a joint operation with federal police.

The Nitro Gym is owned by Comanchero state chapter president Mick Murray.

The fitness centre had been sprayed with bullets in October last year and was nearly blown up when two explosive devices were thrown inside but failed to detonate.

The attack also came in the middle of a tit-for-tat feud with the Hells Angels, who had just set up a new chapter in the area.

But detectives left the gym on Friday without explaining what they were looking for and what prompted the search. A police spokeswoman could not provide any further information about the raids more than six hours after they began, including if anyone had been arrested.

Other properties searched on Friday were located in Narre Warren South, Boronia, Lysterfield South, Hampton Park, Dewhurst and Melbourne.

All have been linked with the Comanchero gang.

Nine firearms were seized from a Dewhurst property while ammunition and a quantity of drugs, believed to be steroids, were seized from a Lynbrook property.

Three men and a woman are being interviewed by police and will face an out of sessions court hearing later tonight if charged.

This is the second major police raid on the club within two months. In February, police hit 62 clubhouses, homes, factories and businesses in what was described as the largest simultaneous police raids in state history.

‘‘It’s not the largest club but it’s causing a lot of concern,’’ Assistant Commissioner Steve Fontana said at the time.

Police say those raids uncovered drugs, cash, explosives, parts for a detonator and a military-style weapon used in a shooting on the Rock Machine clubhouse last year.

The raids had been sparked by police intelligence ,suggesting the Comancheros were about to retaliate against the Hells Angels for a series of previous shootings.

Detectives had also feared the Mongols, which have recently patched over the Finks club in Melbourne, were becoming a front for organised crime.