On Monday, the Palestinians will mark Nakba Day, recalling what they refer to as the "catastrophe" of 1948: Israel's establishment and the expulsion of hundreds of thousands of Palestinians from their land. The day's events will dovetail with the ongoing hunger strike of about 2,000 security prisoners in Israeli jails. The leaders of Fatah and the Palestinian Authority worked hard to ensure that the demonstrations will be confined to the Palestinian cities of the West Bank and will not assume a violent character. However, the IDF is concerned that it will face on May 15 a repeat of last year's Nakba Day when about 100 protesters succeeded in crossing into the state from Syria. In recent weeks, Israel has also passed on messages to UNIFIL in Lebanon warning that the IDF will use force to prevent an infiltration of its border. The Israeli security forces are on high alert.