Reports said the dead included women and children who were discovered in the building where the fire started. The number injured was not disclosed.
Civil defense teams were credited with containing the fire and preventing it from spreading to adjacent structures.
The fire was sparked by gasoline stored in the building, according to preliminary findings, but an investigation is ongoing.
The Palestinian Health Ministry announced that Health Minister Mai al-Kaila ordered the injured to be moved to West Bank hospitals, if necessary.
A statement by Palestinian Presidential spokesman Nabil Abu Rudeineh said President Mahmoud Abbas declared a period of national mourning Friday.
Jabalia is one of eight refugee camps in the area, which is home to 2.3 million people and is one of the world’s most densely populated locations.
Source: Anadolu Agency