WATCH: Heavily-armed police arrest Sydney cash van robbery suspects in violent and dramatic scenes

Four men have been arrested in Sydney after they allegedly pulled off brazen daylight robberies of armoured cash trucks during three separate heists in as many months.

The group is believed to be behind robberies of cash-in-transit security guards in Marrickville in early May and Double Bay and Alexandria in July.

Video shows the dramatic arrests on Monday, with one man being kicked to the ground by police.

The group had armed themselves with pistols, revolvers, crow bars and "long objects" to threaten the guards during the heists, police said, but on the second occasion fled empty-handed.

Police were seen jumping onto the car. Source: 7 News

The group allegedly used two stolen cars - an Audi S3 and a Renault Megane - during their robberies.

Heavily-armed police arrested the suspects on Monday afternoon, using confronting tactics that left at least one man with a bloodied face.

Video shows the violent arrest, a broad daylight ambush in a quiet Cremorne Street.

Police arrested four males. Source: 7 News

Two of the men attempted to run away and one was allegedly in possession of a revolver.

"We heard this really loud pop. We weren't sure if it was a gunshot or something, or a car slamming into another car," a witness said.

The loud pop was an undercover police car deliberately smashing into the stolen vehicle.

Video shows an officer kick one of the men to the ground.

Police were seen kicking one man to the ground. Source: 7 News

Another man managed to make a run for it but was later arrested in a laneway nearby.

The cash-in-transit van was travelling down Cabramatta Road as the Audi lay in wait when police pounced.

The arrests is the culmination of a long-running police investigation.

The group was taken to North Sydney police station for questioning.