Egyptian authorities today closed the Rafah crossing before transit traffic from both sides until tomorrow evening.      An Egyptian official source at the crossing, said the crossing will be re-opened Sunday morning.      Meanwhile a large number of Egyptian youth who will participate in an event known as \"encroachment towards the Palestinian territories,\" scheduled for May 15, the anniversary of the Palestinian Nakba and the announcement of the establishment of the State of Israel, began arriving in Sinai Peninsula, three days ahead of event.     It is noteworthy that the number of transients on both directions of Rafah crossing totaled 30495 people since it was re-opened after the Egyptian revolution. Around 15 thousand people seeking residence, and the number of patients and humanitarian cases arrived in Egypt while 15000 people, including stranded people, Omara (Lesser Pilgrimage) performers, recovered patients, students and expatriate workers, left for Gaza via Rafah crossing.