A major blow has been dealt to overseas crime gangs after 18 arrests and the seizure of more than $21 million worth of drugs in a major Sydney-wide crackdown.

Detectives arrested 18 men allegedly linked to the violent Badger gang, a syndicate based in south-east Asia and behind some of the recent gangland crimes being carried out across Sydney.

Police seized more than $21m worth of drugs.

Police arrested 18 people across Sydney.  NSW Police Force

Detective Superintendent Peter Faux alleged most of the men arrested were middle men for the gang, calling them “the coordinators of the distribution of large amounts of prohibited drugs”.

“We believe that a majority of these people who we have arrested and charged are linked to [the Badger] organised crime network (OCN).

“It brings with it violence, which is what we have seen on the streets, and that’s why we’ve made a concerted effort to target this OCN over the past 18 months,” Faux said.

Police believe they are one of the largest manufacturers and importers of methamphetamine into NSW.

A secretive task force targeting the gang recently seized $77 million worth of drugs, including cocaine, methylamphetamine and ketamine.

The multi-million dollar operation saw multiple raids across Sydney.

The multi-million dollar operation saw multiple raids across Sydney. NSW Police Force

In the past week, a series of raids was carried out across western Sydney, including in Fairfield East, Birrong, Merrylands, Canley Heights and Bankstown.

Eight men were arrested, accused of having varying roles in the network and of distributing drugs across Sydney.

It is being investigated whether the crime gang is linked to the abduction and murder of Bankstown mother Kim Tran in April last year, as well as the foiled plot to kill a father collecting his children from a Revesby daycare last year.

Ties between the Badger syndicate and the Coconut Cartel are also being investigated.

Faux did not rule out further arrests, stating “there will be more charges in the near future”.