Air carrier pilot flying reported experiencing GPS jamming and spoofing while landing and departing from OJMS Airport.

Narrative

During descent into OJMS in day VFR conditions with unlimited visibility; we began to experience GPS jamming. We reported it to the Approach Control and Tower and were able to get radar vectors to final and land uneventfully. During the departure briefing; I briefed the possibility of GPS jamming again and that we needed to call ATC and notify them as well as get radar vectors in case of accuracy issues. After departure from Runway 26 at OJMS and during climb-out and while we were anticipating and experiencing GPS jamming and spoofing; right as we were passing 6000 ft.; again in day VFR conditions and unlimited visibility; we received a GPWS 'terrain; terrain; pull UP' warning. Since we were able to look outside and confirm the message was not valid; we continued the climb normally without taking terrain avoidance actions. Minimum safe altitude in that sector was 4200 ft. We received a second warning going through 14000 ft. My iPad was showing us going back and forth between Cairo and Beirut. ATC was informed about the GPS jamming. Initially they started to give us headings to fly. But when we assessed the navigation integrity in cruise; we realized that we can continue on our own navigation with adequate accuracy of .03 NM. ATC was notified and we were able to continue the flight with no further issues. However; not only other aircraft were reporting GPS jamming; we did not begin to pick up the GPS again until halfway over the Mediterranean Sea.