Four charged over Sydney ice ring

Four men accused of peddling the drug ice throughout Sydney's northwest have been arrested by heavily-armed officers in co-ordinated raids.

Two men, both aged 29, were netted outside a Riverstone shopping centre on Thursday afternoon, while a 35-year-old was arrested at a nearby work site and a 25-year-old at a Guildford home.

All four men are due to appear in court on Friday charged with various gun and drug offences.