RAFAH - Around 3,500 Palestinians crossed Egypt's border with the Gaza Strip since Egypt opened it last Tuesday after Israel's attack on a Gaza-bound aid flotilla, a security source said on Saturday. "More than 700 have crossed the terminal into Egypt while the rest into Gaza," the security source at the crossing told Xinhua. Meanwhile, 25 generators, five ambulances and several thousand sheets and tents have been transported into the besieged strip via the terminal. "Medical aid worth LE30 million ($5.9 million) donated by the Cairo-based Union of Arab Doctors, is expected to enter the strip via the Rafah crossing," the source added. Egyptian President Hosni Mubarak on Tuesday ordered the opening of the crossing indefinitely after Israeli forces attacked an international Gaza-bound convoy of aid ships on Monday and killed at least nine activists.