Three teenagers have been charged with deliberately lighting bushfires over the past two days in Newcastle.

Police say they have charged the boys aged 15, 16 and 17 with lighting bushfires on Thursday and Friday near the John Hunter Hospital at Newcastle.

All the blazes were quickly extinguished by fire crews, police said in a statement.

The 15- and 16-year-old boys were granted bail and will face Broadmeadow Children's Court on February 5.

The 17-year-old boy was refused bail and will face Parramatta Children's Court on Saturday.