Air carrier First Officer reported GPS interference flying through Jeddah airspace.

Narrative

While at cruise altitude of FL300 in Jeddah airspace; we were told our routing via L550 was closed for military reasons. We were cleared direct GAS; direct GIBAL.This routing would have us land ZZZZ with approximately 9.0 fuel. We contacted our dispatcher and inform him of the new routing and fuel situation. He told us we may have to land short of ZZZZ for refueling. Prior to GAS; Jeddah informed us the original routing and airspace was open and cleared us direct to KITOT and flight plan route thereafter. We informed flight control that we were back direct KITOT and fuel would be around 13.0 arriving ZZZZ. While proceeding direct to KITOT we saw several explosions and after burner lights far to our north position. Just prior to KITOT we began experiencing GPS jamming/spoofing. The navigation system degraded to DME DME. We also; received an ATC fault on and off for the transponder. Just prior to CVO; the FO's IPAD showed our location in south Lebanon and continued until just before reaching Greek airspace. While passing CVO; at FL320 we received an erroneous terrain discrepancy. After entering Greek airspace the aircraft GPS and FO's IPAD position returned to normal. At this time we contacted flight control with our current fuel. We agreed to delete our alternate and the dispatcher gave us our new fuel requirement. Flight continued to ZZZZ.