A man has been tasered following several alleged attempted robberies and car jackings in Newcastle today.

Just before 8.30am this morning, police from Newcastle City Local Area Command responded to reports of an armed hold-up at a service station on Maitland Road, Tighes Hill.

Police were told a man entered the store and demanded cash where the attendant complied, handing over cash before the man left.

A short time later, the man approached a woman in a car on Elizabeth Street and allegedly attempted to steal her car but was unsuccessful.

Following his unsuccessful carjacking attempt, he flagged down a taxi and allegedly attempted to rob the driver and steal the vehicle. The taxi driver ran from the vehicle into a nearby industrial store on Elizabeth Street.

The man followed the driver into the store and allegedly attempted to rob three people inside.

He was taken into custody a short time later after a taser was deployed and a knife secured.

The man in his 40s was arrested and taken to Newcastle City Police Station, he was later treated by NSW Ambulance paramedics and taken under police guard to John Hunter Hospital for an existing medical condition.

The man was charged with robbery, assault with intent to take/drive motor vehicle, assault with intent to rob and robbery armed with offensive weapon.

He was refused bail to appear at Newcastle Local Court tomorrow