The Entrance hair salon fire: Four arrested at Marsden Park, Sam Remo and Charmhaven

Police have allegedly seized a gun and over one kilogram of methamphetamine during a series of arrests across western Sydney and Central Coast following an investigation into an arson attack of a hair salon.

Emergency services were called to a hair salon on The Entrance Road, The Entrance, about 2.20am on February 26 following reports of a fire.. (File Picture: Thomas Lisson)

Specialist police have allegedly seized a gun and over one kilogram of methamphetamine during a series of arrests in relation to an investigation into the arson attack of a Central Coast hair salon.

Drug and firearms squad detectives were joined by tactical operations unit officers as they swooped on a vehicle in Marsden Park on Monday night following a two-week investigation into the alleged firebombing of the salon at The Entrance.

Police said they were called to a hair salon on The Entrance Road, The Entrance, about 2.20am on February 26 following reports of a fire.

At the scene, police were told a vehicle reversed into the front of the salon before fuel was poured into the business and set alight.

Fire and smoke damage was sustained to the furniture and building. No injuries were reported.

Police allegedly found a firearm, 1.34kg of methamphetamine, GBH in a syringe, 3.4g of cocaine, electronics, and $2000 cash during a search of a car at Marsden Park. (File picture)

Tuggerah Lakes Police District officers established a crime scene and commenced inquiries into the incident.

Then on Monday night, officers stopped a car in Marsden Park and allegedly found a firearm, 1.34kg of methamphetamine, GBH in a syringe, 3.4g of cocaine, electronics, and $2000 cash.

Four people have now been arrested after the investigation into the alleged arson attack. (File picture)

Two men, aged 19 and 35, were arrested at the scene.

The older man was charged with eight offences including knowingly direct activities of criminal group, aggravated break and enter commit serious indictable offence, destroy etc property in company use fire etc, acquire etc prohibited firearm, possess or use a prohibited weapon without permit, supply prohibited drug (greater than indictable and less than commercial quantity), supply prohibited drug (greater than small and less than or equal to indictable quantity), supply prohibited drug (greater than or equal to large commercial quantity).

The younger man was charged with participate criminal group contribute criminal activity, aggravated break and enter commit serious indictable offence, destroy etc property in company use fire etc, and possess unregistered firearm.

Both men were refused bail to appear before Blacktown Local Court on Tuesday where they were formally refused bail to appear before Gosford Local Court on May 9.

Following further inquiries, officers executed two search warrants at homes in San Remo and Charmhaven on Tuesday.

Two boys – both aged 15 – were arrested and each charged with participate criminal group contribute criminal activity, aggravated break and enter commit serious indictable offence, and destroy etc property in company use fire etc.

Both boys were refused bail to appear before a children’s court on Wednesday.