Emergency services were called to a hotel at the intersection of Union Street and Bull Street at Cooks Hill after reports of an armed robbery just before 5am on Wednesday.

Newcastle police rushed to the scene and immediately started CPR on a man that was found seriously injured on King Street.

Paramedics arrived and took over resuscitation of the man, who was an employee of the hotel and was hurt when he tried to flee from the armed men.

He was taken to John Hunter Hospital in a serious condition.

Police have been told two armed men - one wielding a machete and one a baseball bat - forced their way into the hotel and confronted two staff members.

The armed intruders fled with cash.

They were described as being of Caucasian appearance, aged in their 20s and wearing masks.

The second employee was not physically injured in the ordeal, according to Newcastle police.

Crime scenes have been established and Union Street is closed in both directions between Bull and King streets while officers comb the area for clues.

King Street is also partially closed at the intersection of Union Street and local traffic diversions are in place.

Peak hour travellers should avoid the area if possible.

Multiple highway patrol cars were seen at the scene, as well as several other police vehicles, about 7am, with officers redirecting traffic.

Detectives were at the Cooks Hill hotel on Wednesday morning.

A manhunt is now under way for the assailants.

As investigations continue, any witnesses, anyone who may have dashcam footage, or anyone else that noticed suspicious activity in the area has been urged to contact Newcastle police or Crime Stoppers on 1800 333 000.