Four young men charged in terrifying string of carjackings, armed with firearms and hammers: Dramatic arrests unfold as NSW Police crack down on crime wave

Police have charged four young men over a string of carjackings across Sydney this year.

Four young men have been charged following multiple carjackings across Sydney suburbs.

The alleged incidents in January, February, June and July involved similar events where drivers were approached by unknown men wearing face coverings late at night.

The men allegedly threatened the drivers, in some cases with firearms and hammers, before demanding they get out of the car and fleeing in the vehicle.

State Crime Command detectives backed by riot squad officers on Thursday arrested a 22-year-old man in South Wentworthville, an 18-year-old man in Cranebrook and a 21-year-old man and 17-year-old youth in Parramatta.

The 22-year-old was charged with nine offences including robbery while armed with a dangerous weapon, participating in a criminal group and other drug supply and driving related offences.

He was refused bail and appeared at Parramatta Local Court on Thursday.

The 18-year-old was charged with five offences including taking or driving a vehicle with a person in it while armed with weapon and robbery while armed with a dangerous weapon.

The 21-year-old is also accused of taking or driving a vehicle with a person in it while armed with weapon and participating in a criminal group.

He was refused bail and expected to appear at Parramatta Local Court on Friday.

The 17-year-old was charged with larceny, possessing a prohibited drug, participating in a criminal group and breaching bail.

He was also refused bail and was scheduled to appear before a children's court on Friday.